Calvin Hsia's WebLog : Vista

It's easy to resize your disk volumes on Vista

Calvin_Hsia — Fri, 10 Aug 2007 22:44:00 GMT

On one of my Vista machines, I have a 140G hard drive partitioned into C (20g), D (80G) and E (40g). Drive E was getting full, and I wanted to make it bigger.

Isn’t it ironic that in the year 2007, we still are using letters of the alphabet to refer to all the different kinds of disks (CD, network, USB, thumb, floppy)?

On my PDP-8 computer back in the 70’s, I used OS/8 which used PIP (Peripheral Interchange Program) which referred to peripheral devices with somewhat mnemonic names, such as PTP0: for Paper Tape Punch, DT0: for DecTape unit 0.

Vista now comes with the ability to resize volumes. (On XP, I used a 3^rd party product like Partition Magic). Just Start->right click on Computer, choose Manage, Storage->Disk Management.

Right click on a volume and choose “Shrink” or “Expand”.

I chose to shrink drive D. I expected some sort of progress bar, but just got the wait cursor (spinning circle on Vista) for about 10 minutes, after which I had an unallocated partition show up.

Apparently, Shrink causes the end of the drive to move left, freeing up space. Extend apparently will only extend to the right. IOW, to the left of Drive E was a new unallocated volume, which I could not extend to the left.

So, I could either make it a new volume, or mount the space inside an existing empty NTFS folder (these 2 options are available in WinXP), such as one in drive E:, which expands the available space as seen by programs on drive E.

DLL Image base addresses are the same in XP, different on Vista

Calvin_Hsia — Fri, 27 Jul 2007 21:47:00 GMT

When you start a program on your Windows XP computer, a process is created and several DLLs (Dynamic Link Libraries) are loaded into the process.

Some DLLs are “system” DLLs, such as Kernel32.dll, GDI32.dll, User32.dll.

These DLLs are loaded early in the process start time, because they provide basic operating system functionality, such as input/output, graphics, memory functions.

Each process has a 4 Gigabyte (2 ^ 32) address space, and DLLs are loaded into this address space starting at a particular base address, with a range extending to the size required for that DLL.

If the same DLL is loaded into multiple processes, and it has the same base address, then the entire DLL loaded range is the same for each of these processes and so each process can share the same physical mapping (see Global Descriptor Table)

However, if the DLL is loaded at different base addresses in some processes than others, then the DLL code needs to be modified (rebased) before it is used by the process. This means the same physical memory can not be used, and thus more physical memory (or paged memory) needs to be used.

These DLL code modifications consist of fixups for jumps within the code. For example, there might be a jump instruction embedded in the DLL code. If it’s a relative jump (i.e. jump 10 bytes back), then it doesn’t have to be patched. If it’s an absolute jump (jump to 0x12345678) then it needs to be patched. See also http://en.wikipedia.org/wiki/Import_Address_Table

When you create a DLL, there is a default base address that is in the DLL header. You can examine this default base address for any DLL:

On WinXP SP2, Start->Visual Studio 2005->Visual Studio Tools->Visual Studio command prompt

D:\>link /dump /headers c:\windows\system32\kernel32.dll | more

Dump of file c:\windows\system32\kernel32.dll

PE signature found

File Type: DLL

FILE HEADER VALUES

14C machine (x86)

4 number of sections

46239BD5 time date stamp Mon Apr 16 08:52:53 2007

0 file pointer to symbol table

0 number of symbols

E0 size of optional header

210E characteristics

Executable

Line numbers stripped

Symbols stripped

32 bit word machine

DLL

OPTIONAL HEADER VALUES

10B magic # (PE32)

7.10 linker version

82200 size of code

70000 size of initialized data

0 size of uninitialized data

B5AE entry point (7C80B5AE)

1000 base of code

7F000 base of data

7C800000 image base (7C800000 to 7C8F4FFF)

1000 section alignment

200 file alignment

5.01 operating system version

5.01 image version

4.00 subsystem version

0 Win32 version

F5000 size of image

400 size of headers

F9293 checksum

3 subsystem (Windows CUI)

0 DLL characteristics

40000 size of stack reserve

1000 size of stack commit

100000 size of heap reserve

1000 size of heap commit

0 loader flags

D:\>link /dump /exports c:\windows\system32\kernel32.dll | find /i "createfile"

80 4F 00001A24 CreateFileA

81 50 0000945C CreateFileMappingA

82 51 0000938E CreateFileMappingW

83 52 00010760 CreateFileW

569 238 00064F4D LZCreateFileW

The image base for Kernel32.dll is 0x7c800000

The address of CreateFileW is the sum of the image base (0x7c800000) and the relative address 10760 : 0x7c810760. As you can see from the CreateFile documentation, this API is used to create or open a file. (It also shows that this API is implemented in kernel32.dll.)

A virus writer can depend on this address (0x7c810760) being the same for every Windows XP SP2 machine. Thus a virus can just call code at that address to create or open a file on your machine.

Vista varies the starting address of the system DLLs so that CreateFile will be mapped to a different image base address each time the machine is rebooted, causing virus writers grief.

We’ll talk about how to find the number of modules that are rebased on your system next time.

Help->About->System Info doesn't work on Vista

Calvin_Hsia — Wed, 30 May 2007 01:16:00 GMT

A customer (thanks Grady!) reported that choosing Help->About->System Info on Vista causes a MessageBox to display “Microsoft System Info cannot be found or run.”

Why is that?

Simple investigation: run Regedit on WinXP and Vista to inspect this key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\Msinfo

On Vista, the Type is REG_EXPAND_SZ and the Path is C:\Windows\system32\msinfo32.exe

whereas on XP it’s type is REG_SZ and the Path is C:\Program Files\Common Files\Microsoft Shared\MSInfo\MSInfo32.exe

The MSDN topic Registry Value Types says that REG_EXPAND_SZ can include environment variables, such as %PATH%. However, the Vista value does not have any “%” in it.

The VB version of the Flip Task Bar for Vista Desktop Window Manager

Calvin_Hsia — Tue, 22 May 2007 23:29:00 GMT

In this post: Create your own Flip Task Bar with live thumbnails using Vista Desktop Window Manager DWM, I showed Fox code on creating your own Flip Task bar

Here is the VB.Net version that does the same thing…

File->New->Project->Visual Basic->Windows->Windows Forms Application

View->Code

Paste and run the code below.

Imports System

Imports System.Text

Imports System.Runtime.InteropServices

Public Class Form1

Dim ThumbWidth = 300

Dim ThumbHeight = ThumbWidth * My.Computer.Screen.Bounds.Height / My.Computer.Screen.Bounds.Width

Dim WithEvents cmdQuit As New Button

Dim WithEvents cmdRefresh As New Button

Dim WithEvents oSlider As New TrackBar

Dim WithEvents oTimer As New Timer

Delegate Function EnumWindowsCallback(ByVal hWnd As IntPtr, ByVal lParam As Integer) As Boolean

Declare Ansi Function EnumChildWindows Lib "user32.dll" (ByVal hwnd As IntPtr, ByVal MyCallBack As EnumWindowsCallback, ByVal lParam As Integer) As Boolean

Declare Ansi Function GetWindowTextA Lib "user32.dll" (ByVal hwnd As IntPtr, ByVal Str As StringBuilder, ByVal lSize As Integer) As Integer

Declare Function GetWindowLongA Lib "user32.dll" (ByVal hwnd As IntPtr, ByVal num As Integer) As Integer

Declare Function DwmRegisterThumbnail Lib "dwmapi.dll" (ByVal hWndDest As IntPtr, ByVal hWndSrc As IntPtr, ByRef dwThumb As IntPtr) As Integer

Declare Function DwmUpdateThumbnailProperties Lib "dwmapi.dll" (ByVal hThumb As IntPtr, ByRef dwmp As DWM_PROPERTIES) As Integer

Declare Function DwmUnregisterThumbnail Lib "dwmapi.dll" (ByVal hThumb As IntPtr) As Integer

<StructLayout(LayoutKind.Sequential)> _

Structure POINT

Dim x As Integer

Dim y As Integer

End Structure

<StructLayout(LayoutKind.Sequential)> _

Structure Rect

Sub New(ByVal _left As Integer, ByVal _top As Integer, ByVal _right As Integer, ByVal _bottom As Integer)

Left = _left

Right = _right

Top = _top

Bottom = _bottom

End Sub

Dim Left As Integer

Dim Top As Integer

Dim Right As Integer

Dim Bottom As Integer

End Structure

<StructLayout(LayoutKind.Sequential)> _

Structure DWM_PROPERTIES

Dim dwFlags As Integer

Dim rcDest As Rect

Dim rcSrc As Rect

Dim opacity As Byte

Dim fVisible As Boolean

Dim fSourceClientAreaOnly As Boolean

End Structure

Const DWM_TNP_VISIBLE = 8

Const DWM_TNP_RECTDESTINATION = 1

Const DWM_TNP_OPACITY = 4

Const GWL_STYLE = -16

Const WS_VISIBLE = &H10000000

Const WS_BORDER = &H800000

Class MyWindowItem

Implements IDisposable

Public hWnd As Integer

Public Title As String

Public Tid As IntPtr

Public oPictureBox As MyPictureBox

Public oLabel As Label

Sub New(ByVal _hWnd As Integer, ByVal _title As String)

hWnd = _hWnd

Title = _title

End Sub

Public Sub Dispose1() Implements System.IDisposable.Dispose

If Tid <> 0 Then

DwmUnregisterThumbnail(Tid)

Tid = 0

End If

If oPictureBox IsNot Nothing Then

Form1.Controls.Remove(oPictureBox)

End If

If oLabel IsNot Nothing Then

Form1.Controls.Remove(oLabel)

End If

End Sub

Protected Overrides Sub finalize()

Dispose1()

MyBase.Finalize()

End Sub

End Class

Dim WindowList As New SortedList

Dim nNewWindowsFound As Integer

Dim nTotalWindowsFound As Integer

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

Me.Width = My.Computer.Screen.Bounds.Width

Me.Height = 180

Me.Left = 0

Me.Top = 0

Me.MinimizeBox = False ' no minimize box, so it stays up if user minimizes all

With cmdQuit

.Text = "&Quit"

End With

With cmdRefresh

.Text = "&Refresh"

.Left = 100

End With

With oSlider

.Left = 200

.Minimum = 1

.Maximum = 100

.Value = 50

.LargeChange = 10

.SmallChange = 2

.Height = 400

End With

Me.Controls.Add(cmdQuit)

Me.Controls.Add(cmdRefresh)

Me.Controls.Add(oSlider)

oTimer.Interval = 2000

oTimer.Enabled = True

End Sub

Sub GetHWnds(Optional ByVal fForce As Boolean = True)

If Not fForce Then

nNewWindowsFound = 0

nTotalWindowsFound = 0

Dim nOrigWindowCount = WindowList.Count

EnumChildWindows(0, AddressOf MyCallBack, 0)

If 0 = nNewWindowsFound And nOrigWindowCount = nTotalWindowsFound Then ' no new windows found or none deleted

Return

End If

Dim indx As Integer

Dim cWind As MyWindowItem

For indx = 0 To WindowList.Count - 1

cWind = WindowList.GetByIndex(indx)

cWind.Dispose1()

WindowList.Clear()

nNewWindowsFound = 0

EnumChildWindows(0, AddressOf MyCallBack, 0)

Dim tid As Integer = 0

Dim i = 0

Dim x = 0

Dim y = 20

Dim nRatio = Me.oSlider.Value / Me.oSlider.Maximum

For indx = 0 To WindowList.Count - 1

cWind = WindowList.GetByIndex(indx)

Dim oMyPictureBox As New MyPictureBox

Me.Controls.Add(oMyPictureBox)

With oMyPictureBox

.Left = x

.Top = y

.Height = ThumbHeight * nRatio

.Width = ThumbWidth * nRatio

.GetThumb(cWind)

.Visible = True

End With

cWind.oPictureBox = oMyPictureBox

Dim oLbl As New Label

With oLbl

.Left = x

.Top = y + ThumbHeight * nRatio

.Width = ThumbWidth * nRatio

.Height = 20

.Text = cWind.Title

.Visible = True

End With

cWind.oLabel = oLbl

Me.Controls.Add(oLbl)

x += Me.ThumbWidth * nRatio

If x + Me.ThumbWidth * nRatio > My.Computer.Screen.Bounds.Width Then

x = 0

y += Me.ThumbHeight * nRatio + 20

End If

End Sub

Function MyCallBack(ByVal hWnd As IntPtr, ByVal lParam As Integer) As Boolean

If Me.Handle <> hWnd Then '' if it's not our form

Dim nStyle = GetWindowLongA(hWnd, GWL_STYLE)

If (nStyle And (WS_VISIBLE + WS_BORDER)) = (WS_VISIBLE + WS_BORDER) Then

Dim Caption As New StringBuilder("", 500)

GetWindowTextA(hWnd, Caption, Caption.Capacity)

Dim c As String = Caption.ToString

nTotalWindowsFound += 1

If Not WindowList.ContainsKey(hWnd.ToString) Then

WindowList.Add(hWnd.ToString, New MyWindowItem(hWnd, Caption.ToString))

nNewWindowsFound += 1

End If

Return True

End Function

Private Sub cmdQuit_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmdQuit.Click

Me.Close()

End Sub

Private Sub cmdRefresh_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmdRefresh.Click

GetHWnds()

End Sub

Private Sub Form1_Shown(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Shown

GetHWnds()

End Sub

Private Sub Form1_SizeChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.SizeChanged

End Sub

Private Sub oSlider_ValueChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles oSlider.ValueChanged

GetHWnds()

End Sub

Private Sub oTimer_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles oTimer.Tick

GetHWnds(False)

End Sub

Class MyPictureBox

Inherits PictureBox

Const WS_MINIMIZE = &H20000000

Const SW_RESTORE = &H9

Dim oMyWindow As MyWindowItem

Sub GetThumb(ByVal _oMyWindow As MyWindowItem)

oMyWindow = _oMyWindow

DwmRegisterThumbnail(Me.Parent.Handle, oMyWindow.hWnd, oMyWindow.Tid)

Dim dwmp As New DWM_PROPERTIES

dwmp.opacity = 255

dwmp.fVisible = True

dwmp.rcDest = New Rect(Left, Top, Right, Bottom)

' dwmp.rcSrc = New Rect(0, 0, 200, 200)

dwmp.dwFlags = DWM_TNP_VISIBLE + DWM_TNP_RECTDESTINATION + DWM_TNP_OPACITY

DwmUpdateThumbnailProperties(oMyWindow.Tid, dwmp)

End Sub

<StructLayout(LayoutKind.Sequential)> _

Structure WindowPlacement

Dim length As Integer

Dim flags As Integer

Dim showcmd As Integer

Dim ptMinPosition As POINT

Dim ptMaxPosition As POINT

Dim rcNormalPosition As Rect

End Structure

' Declare Ansi Function GetWindowPlacement Lib "user32.dll" (ByVal hwnd As IntPtr, ByRef wp As WindowPlacement) As Integer

<DllImport("user32.dll", SetLastError:=True)> Shared Function GetWindowPlacement(ByVal hWnd As IntPtr, ByRef wp As WindowPlacement) As Integer

End Function

Declare Ansi Function SetWindowPlacement Lib "user32.dll" (ByVal hwnd As IntPtr, ByRef wp As WindowPlacement) As Boolean

Declare Function SetForegroundWindow Lib "user32.dll" (ByVal hWnd As IntPtr) As Integer

Sub MyClick(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Click

Dim nStyle = GetWindowLongA(oMyWindow.hWnd, GWL_STYLE)

If (nStyle And WS_MINIMIZE) = (WS_MINIMIZE) Then

Dim pPlacement As New WindowPlacement

pPlacement.length = 11 * 4

If GetWindowPlacement(oMyWindow.hWnd, pPlacement) > 0 Then

pPlacement.showcmd = SW_RESTORE

SetWindowPlacement(oMyWindow.hWnd, pPlacement)

Else

Dim n = Marshal.GetLastWin32Error()

Console.WriteLine(n)

End If

SetForegroundWindow(oMyWindow.hWnd)

End Sub

End Class

End of code

What is Vista Aero?

Calvin_Hsia — Wed, 09 May 2007 20:51:00 GMT

I received a question regarding some of my recent posts on Vista:

Forgive my ignorance, but where is Vista Aero. I cannot find it in Vista Ultimate nor have I found it on the MS web pages

I’m sorry: I should have been more clear. Vista Aero is the new graphical user interface for Windows Vista. It displays glass-like transparent borders for windows. I believe it runs on all versions of Vista as long as the machine has a compatible graphics card. In fact, I was not able to run it on my Dell Precision 650 because I had to upgrade my graphics card. I tried upgrading, but apparently the new graphics card had an incompatibility with my disk drive controller.

I believe that Aero will be enabled by default when installing Vista on a machine with a compatible graphics controller.

I recently borrowed a Vista Aero capable machine, and thus was able to explore some of the Aero features.

My prior post shows how to create your own Windows Flip (Alt-Tab display) in Foxpro, and I already have it working in VB.Net for a future post.

You can see Aero at http://www.microsoft.com/windows/products/windowsvista/features/experiences/aero.mspx

Create your own Flip Task Bar with live thumbnails using Vista Desktop Window Manager DWM

Calvin_Hsia — Sun, 06 May 2007 07:13:00 GMT

The sample below uses Desktop Window Manager under Windows Vista with Aero to get dynamic live thumbnails of running applications. If a movie is playing in Windows Media Player, it will play in the thumbnail too!

EnumChildWindows or EnumWindows is used to enumerate all running windows created by the various processes on your machine.

I extracted code from: How does EventHandler work? IConnectionPoint! to make the CAsmLib class to generate assembly code. The sample below uses the class to generate ASM code that gets called by EnumChildWindows and calls _VFP.DoCmd method to insert the Window handles found into a cursor.

On both XP and Vista, the code will generate a cursor with Window Handles and their titles.

A SQL statement executed in a timer routine determines if any new processes were added and if so, to refresh the display.

SELECT hWnd,Title FROM NewTopLevel WHERE hWnd NOT in (SELECT hWnd FROM TopLevel) UNION ;

SELECT hWnd,Title FROM TopLevel WHERE hWnd NOT in (SELECT hWnd FROM NewTopLevel) ;

INTO CURSOR temp

If you’re running on Vista and DwmIsCompositionEnabled, the code will then create a form and an array of live thumbnails on it. The form uses an array of invisible commandbuttons for each thumbnail. Using an Image control without an image displays a cross. All we’re doing is providing an hWnd and a rect for DWM to draw the thumbnail.

(Vista Aero can have DwmIsCompositionEnabled enabled or disabled. See Control Panel->System and Maintenance->System->Advanced System Settings->Advanced->Performance->Settings->Visual Effects->Enable desktop composition)

GetWindowThreadProcessId is called to get the Process Id of the window handle.

Play a movie: make it repeat if it’s short, do things in other windows, and you’ll see the thumbnails update on the form. Hit Alt-Tab (or Alt-Ctrl-Tab to keep the flip display on, or even WindowsKey-Tab), and you’ll see the thumbnail still live. Use the slider to changes the size of the thumbnails. You can even make the thumbs larger than the source application!

Click on a thumbnail to make it the foreground application. Resize the thumbnail form. Modify source windows by editing text, etc. Hit WindowKey->M to minimize all windows.

CLEAR ALL

CLEAR

MODIFY COMMAND PROGRAM() NOWAIT

SET SAFETY OFF

PUBLIC oForm

oForm=CREATEOBJECT("CThumbForm")

#define WS_VISIBLE 0x10000000

#define WS_BORDER 0x00800000

DEFINE CLASS CThumbForm as Form

ShowWindow=2 && Top Level

width=SYSMETRIC(1) && entire width of display

height=100

MinButton=.f. && don't allow minimize for us

nThumbs=0 && number of thumbs currently on form

fDWM = .f. && are we running under Vista Desktop Window Management?

nThumbWidth=400 && size of thumb to draw

nThumbHeight=this.nThumbWidth * SYSMETRIC(2)/SYSMETRIC(1) && same aspect ratio as desktop

ADD OBJECT cmdQuit as CommandButton WITH Caption="\<Quit",cancel=.t.

ADD OBJECT cmdRefresh as CommandButton WITH Caption="\<Refresh",left=120

ADD OBJECT oSlider as cSlider WITH left=250

ADD OBJECT oTimer as Timer WITH interval=2000 && millisecs

PROCEDURE oTimer.Timer

thisform.GetHWnds("NewTopLevel")

SELECT hWnd,Title FROM NewTopLevel WHERE hWnd NOT in (SELECT hWnd FROM TopLevel) UNION ;

SELECT hWnd,Title FROM TopLevel WHERE hWnd NOT in (SELECT hWnd FROM NewTopLevel) ;

INTO CURSOR temp

IF _Tally>0 && a new window was created or destroyed

thisform.GetThumbNails() && ToDo: optimize for only the change

ENDIF

PROCEDURE cmdRefresh.Click

thisform.GetThumbNails()

PROCEDURE cmdQuit.Click

thisform.release

PROCEDURE Init

SET TALK OFF

IF VAL(OS(3))>=6 && runnning under Vista. Check for Desktop Compostion enabled

DECLARE integer DwmIsCompositionEnabled IN dwmapi integer @ dwEnabled

dwEnabled=0

IF DwmIsCompositionEnabled(@dwEnabled) = 0 AND dwEnabled>0

this.fDWM = .t.

ENDIF

IF this.fDWM

DECLARE integer DwmRegisterThumbnail IN dwmapi integer hwndDest, integer hwndSrc, integer @ nThumbnailId

DECLARE integer DwmUnregisterThumbnail IN dwmapi integer nThumbnailId

DECLARE integer DwmQueryThumbnailSourceSize IN dwmapi integer nThumbnailId, string @pSize

DECLARE integer DwmUpdateThumbnailProperties IN dwmapi integer hThumbnailId, string @ ptnProperties

DECLARE integer SetForegroundWindow IN WIN32API integer

DECLARE integer GetWindowPlacement IN WIN32API integer hWnd, string @ pPlacement

DECLARE integer SetWindowPlacement IN WIN32API integer hWnd, string @ pPlacement

this.Visible=1

* this.GetThumbNails() && Resize will call GetThumbNails

ELSE

NEWOBJECT("CEnumWindows") && call the class that creates the cursor of hWnds

LOCATE && go to the top of the cursor

BROWSE LAST NOWAIT

RETURN .f. && don't create form

ENDIF

PROCEDURE Resize

this.GetThumbNails()

PROCEDURE GetHWnds(DestCursor as string)

NEWOBJECT("CEnumWindows") && call the class that creates the cursor of hWnds

SELECT * FROM hwnds WHERE BITAND(style,WS_VISIBLE+WS_BORDER) = WS_VISIBLE+WS_BORDER AND ;

hWnd != thisform.HWnd ;

INTO CURSOR (DestCursor) && Only those hWnds which are visible and have a border

RETURN _tally

PROCEDURE GetThumbNails

LOCAL cStr,oLbl,cName,x,y,oi

thisform.LockScreen= .T.

FOR indx = 1 TO thisform.nThumbs

cName="im"+PADL(indx,3,"0") && im001, im002...

thisform.RemoveObject(cName)

IF TYPE("thisForm."+cName+"lbl")="O"

thisform.RemoveObject(cName+"lbl")

ENDIF

ENDFOR

thisform.nThumbs=this.GetHWnds("TopLevel")

INDEX on hwnd TAG hwnd

nRatio = thisform.oSlider.Value/thisform.oSlider.max

x = 0

y = 20

indx=1

SCAN

cName="im"+PADL(indx,3,"0") && im001, im002...

thisform.AddObject(cName,"CThumb")

cStr="Thisform."+cName

oi = EVALUATE(cStr)

oi.Height = this.nThumbHeight * nRatio

oi.Width = this.nThumbWidth * nRatio

oi.Left = x

oi.Top = y

oi.visible=1

oi.RegThumb(hWnd,ALLTRIM(title))

indx=indx+1

x = x + this.nThumbWidth* nRatio

IF x + this.nThumbWidth* nRatio > thisform.Width

x=0

y = y + this.nThumbHeight* nRatio+20

ENDIF

ENDSCAN

thisform.LockScreen= .f.

ENDDEFINE

DEFINE CLASS cSlider AS Olecontrol

OleClass="mscomctllib.slider.2"

PROCEDURE Init

this.min=1

this.max=100

this.value=INT(this.max/5)

this.SmallChange=INT(this.max/50)

this.LargeChange=INT(this.max/5)

PROCEDURE Change && when the slider value changes

thisform.GetThumbNails()

ENDDEFINE

#define GWL_STYLE 0xfffffff0

#define WS_MINIMIZE 0x20000000

#define SW_RESTORE 9

#define DWM_TNP_RECTDESTINATION 1

#define DWM_TNP_RECTSOURCE 2

#define DWM_TNP_OPACITY 4

#define DWM_TNP_VISIBLE 8

#define DWM_TNP_SOURCECLIENTAREAONLY 0x10

DEFINE CLASS CThumb as CommandButton

nThumbId = 0

style=1 && invisible

enabled=.t.

hWnd=0

PROCEDURE click && user clicked on thumbnail: let's activate it

IF BITAND(GetWindowLong(this.hWnd,GWL_STYLE), WS_MINIMIZE) > 0 && if window is minimized

pPlacement=BINTOC(11*4,"4rs") + SPACE(10*4) && 11 4 byte words

IF GetWindowPlacement(this.hWnd, @pPlacement) > 0

pPlacement = LEFT(pPlacement,2*4) + BINTOC(SW_RESTORE,"4rs")+SUBSTR(pPlacement,13) && Restore it

SetWindowPlacement(this.hWnd, @pPlacement)

ENDIF

SetForegroundWindow(this.hWnd)

PROCEDURE RegThumb(hWnd as Integer,cTitle as String)

LOCAL cStr,oLbl,cName

nResult=0

this.hWnd=hWnd

IF DwmRegisterThumbnail(thisform.hWnd, m.hWnd, @nResult ) = 0 AND nResult > 0

this.nThumbId = nResult

cName=this.Name+"lbl" && iml001002lbl

cStr="thisform."+cName

thisform.AddObject(cName,"Label")

oLbl=EVALUATE(cStr)

WITH oLbl as Label

.Top=this.Top+this.Height

.Left = this.Left

.Width = MAX(this.Width-10,0)

.Height = 20

.Caption=cTitle

.Visible=1

ENDWITH

* @this.Left,this.top+this.Height say cTitle

cStr=SPACE(8)

*!* ?"TSize",DwmQueryThumbnailSourceSize(nResult, @cStr) && gets the size of the Source window

*!* ?CTOBIN(LEFT(cStr,4),"4rs"),CTOBIN(RIGHT(cStr,4),"4rs")

dwFlags= DWM_TNP_RECTDESTINATION + DWM_TNP_OPACITY + DWM_TNP_VISIBLE

nOpacity = 255 && can make the thumbnails glass

fVisible= 1 && make the thumb visible?

fSourceClientAreaOnly = 0 && just client area of source thumbnail?

rDest= ;

BINTOC(this.Left,"4rs") + ;

BINTOC(this.Top,"4rs") + ;

BINTOC(this.Left + this.Width,"4rs") + ;

BINTOC(this.Top+this.Height,"4rs") && where to render the thumbnail

rSrc= ;

BINTOC(0,"4rs") + ;

BINTOC(0,"4rs") && rSrc: region of thumbnail to render. We'll use the whole src image

cProps = ;

BINTOC(dwFlags,"4rs") + ;

rDest + ;

rSrc + ;

CHR(nOpacity) + ;

BINTOC(fVisible,"4rs") + ;

BINTOC(fSourceClientAreaOnly,"4rs")

hr =DwmUpdateThumbnailProperties(nResult, @ cProps)

ENDIF

PROCEDURE destroy

IF this.nThumbId > 0

DwmUnregisterThumbnail(this.nThumbId)

ENDIF

ENDDEFINE

DEFINE CLASS CEnumWindows AS CAsmLib

PROCEDURE Init

DODEFAULT() && call parent class Init

DECLARE integer GetWindowText IN WIN32API integer, string @, integer

DECLARE integer GetWindowLong IN WIN32API integer, integer

DECLARE integer GetWindowThreadProcessId IN WIN32API integer hWnd, integer @ pid

CREATE cursor HWnds (hWnd i, title c(100), style i,pid n)

this.CreateEnumWindowCode("INSERT INTO HWnds (hWnd) VALUES (%d)") && use this cmd to insert a record into the cursor

SELECT hWnds && Now scan through the cursor and get the window titles and styles

SCAN

cText=SPACE(100)

nLen=GetWindowText(hWnd,@cText,LEN(cText)) && Get the title of the window

mPid=0

GetWindowThreadProcessId(hWnd,@mpid) && Get the window's ProcessID

REPLACE title WITH LEFT(cText,nLen) ,style WITH GetWindowLong(hWnd,GWL_STYLE),pid WITH mPid

ENDSCAN

PROTECTED PROCEDURE CreateEnumWindowCode(cCmd as String)

*This simple code doesn't need jumps, but included anyway for general usefulness for branching code

CREATE CURSOR jumps (cLabel c(20),cFlag c(1),sCodePos i) && cFlag="D" defined, "R", reference

INDEX on cLabel+cFlag TAG cLabel

nLocals=0x60 && enough space for local vars

sCode=""

sCode = sCode + CHR(0x55) && push ebp

sCode = sCode + CHR(0x8b) + CHR(0xec) && mov ebp, esp

sCode = sCode + CHR(0x81) + CHR(0xec)+BINTOC(nLocals * 4, "4rs") && sub esp, nLocals

*!* sCode = sCode + CHR(0x6a) + CHR(0x00) && push 0

*!* sCode = sCode + this.CallDllFunction("MessageBeep", "user32") && MessageBeep(0)

* sCode = sCode + CHR(0xcc) && int 3 DebugBreak() to attach a debugger

*swprintf(ebp-a0h, 0x30,cCmd,hWnd) && replace the "%d" with the hWnd: "INSERT INTO HWnds (hWnd) VALUES (%d)"

sCode = sCode + CHR(0x8b) + CHR(0x45) + CHR(0x08) && mov eax, [ebp+8] && get the hWnd

sCode = sCode + CHR(0x50) && push eax

sCode = sCode + CHR(0xb8) + BINTOC(this.MakeStr(cCmd,.t.),"4rs") && mov eax, str (Unicode)

sCode = sCode + CHR(0x50) && push eax

sCode = sCode + CHR(0x8d) + CHR(0x45)+CHR(0xa0) && lea eax, [ebp-a0h] && addr to put swprintf result

sCode = sCode + CHR(0x50) && push eax

sCode = sCode + this.CallDllFunction("swprintf", "msvcrt") && swprintf(ebp-a0h, 0x30,cCmd,hWnd)

sCode = sCode + CHR(0x83)+ CHR(0xc4)+ CHR(0xc) && add esp, 0ch pop 3*4 _cdecl args

*SysAllocString() This string for each window,so it must be freed with SysFreeString below

sCode = sCode + CHR(0x8d) + CHR(0x45)+CHR(0xa0) && lea eax, [ebp-a0h] && addr of swprintf result

sCode = sCode + CHR(0x50) && push eax

sCode = sCode + this.CallDllFunction("SysAllocString", "oleaut32") && SysAllocString

*_vfp.DoCmd()

sCode = sCode + CHR(0x89) + CHR(0x45) + CHR(0xf0) && mov [ebp-10h], eax ; save the bstr so we can free it

sCode = sCode + CHR(0x50) && push eax

sCode = sCode + CHR(0xb8) + BINTOC(SYS(3095,_vfp),"4rs") && mov eax, the IDispatch for _VFP

sCode = sCode + CHR(0x50) && push eax && the THIS pointer(_vfp)

sCode = sCode + CHR(0x8b) + CHR(0) && mov eax, [eax] && get the vTable

sCode = sCode + CHR(0x05) + BINTOC(0x84,"4rs") && add eax, 84h the function at 84h in the vTable, which is DoCmd

sCode = sCode + CHR(0xff) + CHR(0x10)&& call [eax] && call indirect

sCode = sCode + CHR(0x83) + CHR(0xf8) + CHR(0x00) && cmp eax, 0 && if hr = SUCCESS

* jne FailedDoCmd

sCode = sCode + CHR(0x75)+CHR(0x00) && jne nBytes && nBytes calc'd below. je= 0x74, Jump if Equal, jne = 0x75

INSERT INTO jumps values ("FailedDoCmd","R",LEN(sCode)) && refer to a label to jump to at this pos

*else { //FailedDoCmd

INSERT INTO jumps values ("FailedDoCmd","D",LEN(sCode)) && define a label at this pos

* now free the bstr

sCode = sCode + CHR(0x8b) + CHR(0x45) + CHR(0xf0) && mov eax, [ebp-10h]

sCode = sCode + CHR(0x50) && push eax

sCode = sCode + this.CallDllFunction("SysFreeString", "oleaut32") && vswprintf(ebp-a0h, 0x30,cCmd,hWnd)

sCode = sCode + CHR(0xb8) + BINTOC(1,"4rs") && mov eax, 1 && return 1 so Enum continues

* sCode = sCode + CHR(0x33) + CHR(0xc0) && xor eax,eax && make return value 0 so won't enum any more windows

sCode = sCode + CHR(0x8b) + CHR(0xe5) && mov esp, ebp

sCode = sCode + CHR(0x5d) && pop ebp

sCode = sCode + CHR(0xc2)+CHR(0x08)+CHR(0x00) && ret 8 && EnumChildProc has 2 parms: pop 2 args=8 bytes

USE jumps AGAIN IN 0 ORDER 1 ALIAS jumpdefs

SCAN FOR cFlag="R" && look for all references

=SEEK(jumps.cLabel+"D","jumpdefs")

sCode=LEFT(sCode,jumps.sCodePos-1)+CHR(jumpdefs.sCodePos - jumps.sCodePos) + SUBSTR(sCode,jumps.sCodePos+1) && now fix up the jump location to jump to the definition

ENDSCAN

AdrCode=this.memAlloc(LEN(sCode),sCode) && allocate memory for the code

EnumChildWindows(0,AdrCode,0) && EnumChildWindows needs a callback function. We'll give it our code.Added benefit: Win32 Exception handling of Declare dll

USE IN jumpdefs

USE IN jumps

ENDDEFINE

DEFINE CLASS CAsmLib as Custom && utility to help generate ASM code

hProcHeap =0

PROCEDURE Init

SET ASSERTS ON

DECLARE integer LoadLibrary IN WIN32API string

DECLARE integer FreeLibrary IN WIN32API integer

DECLARE integer GetProcAddress IN WIN32API integer hModule, string procname

DECLARE integer GetProcessHeap IN WIN32API

DECLARE integer HeapAlloc IN WIN32API integer hHeap, integer dwFlags, integer dwBytes

DECLARE integer HeapFree IN WIN32API integer hHeap, integer dwFlags, integer lpMem

DECLARE integer CLSIDFromString IN ole32 string lpszProgID, string @ strClSID

DECLARE integer SysAllocString IN oleaut32 string wstr

DECLARE integer SysFreeString IN oleaut32 integer bstr

DECLARE integer EnumChildWindows IN WIN32API integer hWnd, integer lpEnumProc, integer lParam

CREATE CURSOR memAllocs (memPtr i, AllocType c(1)) && track mem allocs that need to be freed: H=Heap,B=BSTR,L=Library

this.hProcHeap = GetProcessHeap()

PROCEDURE MemAlloc(nSize as Integer, cStr as String) as Integer

LOCAL nAddr

nAddr = HeapAlloc(this.hProcHeap, 0, nSize) && allocate memory

ASSERT nAddr != 0 MESSAGE "Out of memory"

INSERT INTO memAllocs VALUES (nAddr,"H") && track them for freeing later

SYS(2600,nAddr, LEN(cStr),cStr) && copy the string into the mem

RETURN nAddr

PROCEDURE CallDllFunction(strExport as String, strDllName as String) as String

*Create a string of machine code that calls a function in a DLL. Parms should already be pushed

LOCAL nAddr as Integer, hModule as Integer

hModule = LoadLibrary(strDllName)

INSERT INTO memAllocs VALUES (hModule,"L") && track loads for freeing later

nAddr=GetProcAddress(hModule,strExport)

ASSERT nAddr != 0 MESSAGE "Error: Export not found "+ strExport+" "+ strDllName

RETURN CHR(0xb8)+BINTOC(nAddr,"4rs") + CHR(0xff) + CHR(0xd0) && mov eax, addr; call eax

PROCEDURE MakeStr(str as String, fConvertToUnicode as Logical, fMakeBstr as Logical) as Integer

* converts a string into a memory allocation and returns a pointer

LOCAL nRetval as Integer

IF fConvertToUnicode

str=STRCONV(str+CHR(0),5)

ELSE

str = str + CHR(0) && null terminate

ENDIF

IF fMakeBstr

nRetval= SysAllocString(str)

ASSERT nRetval != 0 MESSAGE "Out of memory"

INSERT INTO memAllocs VALUES (nRetval,"B") && track them for freeing later

ELSE

nRetval= this.MemAlloc(LEN(str),str)

ENDIF

RETURN nRetval

PROCEDURE Destroy

LOCAL i,nSel

nSel=SELECT()

SELECT memAllocs

SCAN

DO CASE

CASE AllocType="B" && BSTR

SysFreeString(memPtr)

CASE AllocType="H" && Heap

HeapFree(this.hProcHeap,0,memPtr)

CASE AllocType="L" && LoadLibrary

FreeLibrary(memPtr)

ENDCASE

ENDSCAN

USE

SELECT (nSel)

ENDDEFINE

End Of Code

Vista Aero DWM seems to optimize out GDI paint calls

Calvin_Hsia — Fri, 04 May 2007 02:50:00 GMT

In this post: Foxpro Menu items, combo boxes not refreshing selected item under Aero in Vista I describe a problem in Foxpro where menu and list items that are supposed to be non-selected aren’t painted correctly. I described a workaround: call the GdiSetBatchLimit API, which limits the GDI paint functions that are batched. Apparently some calls are being optimized out or not executed.

The problem occurs whether run as Administrator or not, but requires Desktop Composition enabled.

On Windows XP, the program runs as expected.

I’ve managed to create a standalone simple C++ program that demonstrates the behavior. The entire VS 2005 project is available here

The program displays a dozen items with the first item selected (inverted colors). The user can hit the down or up arrows to move the selection. If you hit the down arrow once, the first item is painted unselected, and the next item is painted selected. That’s fine. If you hit down arrow a few more times, the prior item doesn’t get repainted unselected.

I’ve put a call to GdiSetBatchLimit on Left or Right Arrow. Left will set it to 1, Right to 20 (the default). If you hit the left arrow, then the list selection behaves normally (you don’t even have to restart the app). Right arrow reproduces the problem behavior.

The problem seems related to calling SelectClipRgn

To create the sample project:

Start VS 2005: choose File->New Project-> Visual C++ Win32 Win32 Project. Call it VistaItems

In the Win32 Application Wizard, just choose all the defaults and Finish.

In the WndProc, add this case in the Switch to handle the WM_CREATE message:

case WM_CREATE:

{

RECT rect;

GetClientRect(hWnd,&rect);

rect.right/=2;

rect.left= 50;

CMenuWin *pCMenuWin = new (CMenuWin);

HWND hwndChild =

pCMenuWin->Create(hWnd, &rect,L"CMenuWin",

WS_VISIBLE | WS_CLIPCHILDREN | WS_POPUP

, WS_EX_NOPARENTNOTIFY);

if (hwndChild == 0)

{

int n = GetLastError();

DebugBreak();

}

SetParent(hwndChild, hWnd);

g_hwndChild = hwndChild;

}

break;

case WM_KEYDOWN:

return SendMessage(g_hwndChild, message, wParam, lParam);

break;

Add these lines after this line #include "VistaItems.h"

#include "atlbase.h"

#include "atlwin.h"

#define NUMITEMS 12

#define MAXITEMSIZE 10

struct DATA

{

TCHAR strText[MAXITEMSIZE];

int nState; // 0 or 1: selected or not

} Data[NUMITEMS] = {L"One",1,L"Two",0,L"Three",0,L"Four",0,

L"Five",0,L"Six",0,L"Seven",0,L"Eight",0,

L"Nine",0,L"Ten",0,L"Eleven",0,L"Twelve",0

};

int g_nCurItem = 0;

HDC g_hdc=0;

void GetRect(int nIndex, RECT * rect)

{

rect->left=10;

rect->right = 400;

rect->top = nIndex * 20;

rect->bottom = rect->top + 20;

}

void ShowItems(HWND hWnd, int nIndex, HDC hdc)

{

RECT rect;

GetRect(nIndex, &rect);

HFONT hFont = (HFONT)GetStockObject(ANSI_VAR_FONT);

COLORREF clr, clrold;

Data[nIndex].nState = 1 - Data[nIndex].nState ; // invert state

if (Data[nIndex].nState == 0)

{

clr = RGB(255,0,0);

SetBkColor(hdc, RGB(0,0,0));

} else

{

clr = RGB(0,0,255);

SetBkColor(hdc, RGB(255,255,255));

}

clrold = SetTextColor(hdc, clr);

ExtTextOut(hdc,

rect.left, rect.top, ETO_CLIPPED | ETO_OPAQUE ,

&rect, Data[nIndex].strText,(int)wcslen(Data[nIndex].strText), 0);

SetTextColor(hdc, clrold);

}

HRGN g_hRgn = 0;

HWND g_hwndChild = 0;

class CMenuWin : public CWindowImpl<CMenuWin>

{

public:

// DECLARE_WND_CLASS_EX(L"CMenuWin", 0 /*CS_OWNDC*/, COLOR_MENUHILIGHT) // backcolor

BEGIN_MSG_MAP(CMenuWin)

MESSAGE_HANDLER(WM_KEYDOWN,OnKeyDown)

MESSAGE_HANDLER(WM_PAINT,OnPaint)

END_MSG_MAP()

LRESULT OnKeyDown(UINT uMsg,WPARAM wParam, LPARAM lParam, BOOL & bHandled)

{

HDC hdc;

hdc = GetDC();

if (g_hRgn) {

DeleteObject(g_hRgn);

g_hRgn = 0;

}

RECT rect;

GetRect(g_nCurItem, &rect);

g_hRgn = CreateRectRgnIndirect(&rect);

SelectClipRgn(hdc,g_hRgn);

ShowItems(m_hWnd, g_nCurItem, hdc);

switch(wParam)

{

case VK_LEFT: // hit left arrow

GdiSetBatchLimit(1); // this will make it behave as expected

break;

case VK_RIGHT: // hit right arrow

GdiSetBatchLimit(20); // this will show the broken behavior

break;

case VK_DOWN: // down arrow

if (++g_nCurItem == NUMITEMS)

{

g_nCurItem=0;

}

break;

case VK_UP:

if (g_nCurItem-- == 0)

{

g_nCurItem=NUMITEMS-1;

}

break;

}

if (g_hRgn) {

DeleteObject(g_hRgn);

g_hRgn = 0;

}

GetRect(g_nCurItem, &rect);

g_hRgn = CreateRectRgnIndirect(&rect);

SelectClipRgn(hdc,g_hRgn);

ShowItems(m_hWnd, g_nCurItem, hdc);

ReleaseDC(hdc);

return 0;

}

LRESULT OnPaint(UINT uMsg,WPARAM wParam, LPARAM lParam, BOOL & bHandled)

{

PAINTSTRUCT ps;

HDC hdc = BeginPaint(&ps);

for (int i = 0 ; i < NUMITEMS ; i++)

{

ShowItems(m_hWnd, i, hdc);

}

EndPaint(&ps);

return 0;

}

};

End of code

Fun with Vista Aero using the DwmExtendFrameIntoClientArea

Calvin_Hsia — Wed, 02 May 2007 21:21:00 GMT

You can have a little fun with Vista Aero using the DwmExtendFrameIntoClientArea function.

This will cause the VFP border to paint the glass effect around the fox border

DECLARE integer DwmExtendFrameIntoClientArea IN dwmapi integer hWnd, string @ daMargins

cStr=REPLICATE(BINTOC(100,"4rs"),4)

_screen.BackColor=0

_screen.ForeColor=-1

DwmExtendFrameIntoClientArea (_vfp.HWnd, @cStr)

RETURN

For your own forms, try this:

PUBLIC x

x=CREATEOBJECT("myForm")

x.show

DEFINE CLASS MyForm AS Form

ShowWindow= 2 && top level form

PROCEDURE Init

DECLARE integer DwmExtendFrameIntoClientArea IN dwmapi integer hWnd, string @ daMargins

cStr=REPLICATE(BINTOC(100,"4rs"),4)

this.BackColor=0

this.ForeColor=-1

DwmExtendFrameIntoClientArea (this.HWnd, @cStr)

ENDDEFINE

For more fun, stay tuned…

Windows Vista Aero BorderStyle Paint problem as non Administrator

Calvin_Hsia — Wed, 02 May 2007 00:30:00 GMT

Above is an image of an inner form (from the C++ project below) before and after I dragged it a little bit up and left to obscure the title bar, then back to the original position. You can see the title, icon, close/minimize buttons were not painted correctly. The same thing happens in Foxpro and VS 2005.

In my prior post, Fix your forms to paint borders correctly under Vista Aero, I showed how Vista Aero doesn’t allow a window that already exists to change its border unless running as an Administrator.

If you run VS 2005 on Vista with Aero as a non-administrator, you can reproduce the same problem with the Windows Form Designer:

Start VS 2005, choose File->New->Visual Basic->Windows Application

Click on the form in the Form designer to select it, then change the FormBorderStyle property to FixedSingle

Now hover your mouse over the ToolBox to make it appear over the form in the designer. Then move your mouse away to let it disappear (or cause any other VS Window to cover the form).

You’ll see that the Titlebar of the form doesn’t get painted correctly: remnants of the toolbox still exist on the title bar. It works fine running VS as Administrator, Vista without Aero, or Windows XP.

I didn’t install C# on this recently borrowed Vista Aero machine, so I can’t test it, but I suspect it’s the same behavior because it’s the same form designer.

Here’re a few lines of sample C++ code that isolates the problem. (Zip file of VS2005 project with EXE available here)

The program simulates a form designer: it creates a child window with a caption initially, turns off the caption, then turns it back on.

Note that for Windows Styles, WS_CAPTION = WS_BORDER | WS_DLGFRAME

Start VS 2005: choose File->New Project-> Visual C++ Win32 Win32 Project. Call it VistaPaint

In the Win32 Application Wizard, just choose all the defaults and Finish.

Add these lines after this line #include "VistaPaint.h",

#include "atlbase.h"

#include "atlwin.h"

class CForm2 : public CWindowImpl<CForm2>

{

public:

DECLARE_WND_CLASS_EX(L"CForm2", 0, COLOR_MENUHILIGHT) // backcolor

BEGIN_MSG_MAP(CForm2)

END_MSG_MAP()

};

and in the WndProc, add this case in the Switch to handle the WM_CREATE message:

case WM_CREATE:

{

RECT rect;

GetClientRect(hWnd,&rect);

rect.bottom /=2;

rect.right/=2;

CForm2 *pCForm2 = new (CForm2);

pCForm2->Create(hWnd, &rect,L"CForm2",

, /*WS_EX_DLGMODALFRAME |*/ WS_EX_WINDOWEDGE | WS_EX_NOPARENTNOTIFY);

SetWindowLong(pCForm2->m_hWnd, GWL_STYLE, GetWindowLong(pCForm2->m_hWnd, GWL_STYLE) & ~( WS_CAPTION | WS_SYSMENU) ); // turn off caption (WS_CAPTION = WS_BORDER | WS_DLGFRAME )

SetWindowLong(pCForm2->m_hWnd, GWL_STYLE, GetWindowLong(pCForm2->m_hWnd, GWL_STYLE) | ( WS_CAPTION | WS_SYSMENU) ); // turn on caption (WS_CAPTION = WS_BORDER | WS_DLGFRAME )

}

break;

Last, change the InitInstance code to add the WS_CLIPCHILDREN flag: Change the CreateWindow line in InitInstance from

hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,

CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);

hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW | WS_CLIPCHILDREN ,

CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);

Now hit F5 to run the code. Move the inner window inside the outer to cause the border to repaint. Observe the border doesn’t get repainted.

Now run the same app as an Administrator (start Windows Explorer, navigate to the Project Debug directory, right click on the EXE file and choose Run as Administrator). Observe that the border paints correctly.

For even more fun, comment out the DECLARE_WND_CLASS_EX line!

Fix your forms to paint borders correctly under Vista Aero

Calvin_Hsia — Sat, 28 Apr 2007 03:31:00 GMT

Apparently, the borders of some forms don’t get painted correctly on Windows Vista.

When executing a Fox Form, Fox asks Windows to create a window, then sets the BorderStyle of the window. Apparently, under Vista Aero (except as Administrator), the BorderStyle cannot be set after the Window has been created.

To reproduce the problem, start Visual FoxPro (I tried back to VFP7 (released summer 2001))

File->New->Form
In the property sheet, dbl-click BorderStyle to change it to 1 or 2

0 = No border ( no problem, because there are no borders to draw)
1 = Fixed Single
2 = Fixed Dialog
3 = Sizable (Default) (no problem, because it’s the default)

Hit Ctrl-E or click on the “!” in the toolbar to run the form. Give it a name
Move the form around so that the borders or title bar will need to be repainted
Result: The window behaves as if there is no border: it won’t get repainted.

Amazingly enough, run under Admin mode, and you’ll see the problem disappear. Perhaps a non-admin app changing the BorderStyle might be a security risk: An app might be able to grab a window handle from another process and impersonate a Credentials screen or something.

When Fox runs a form, it reads the Properties and sets them in the order encountered. For a Form, the “DoCreate” pseudo property means to create the window. The BorderStyle happens to be written after the DoCreate, so the BorderStyle setting is ignored

The properties look like this before the fix:

Top = 0

Left = 0

Height = 250

Width = 375

DoCreate = .T.

BorderStyle = 1

Caption = "Form1"

Name = "Form1"

So your choices are:

Open the Form as a table (It really is just a table) and manually put BorderStyle before DoCreate.
Run the program below that fixes your SCX files by putting the BorderStyle property before the DoCreate
Convert your SCX forms to VCX (Visual Classes), where the BorderStyle is set at window creation time. (Just choose File->Save As Class from the Form designer)
Wait for the next release of VFP SP
Run Vista without Aero
Run your app as Admin

Foxpro Menu items, combo boxes not refreshing selected item under Aero in Vista

Calvin_Hsia — Thu, 26 Apr 2007 21:28:00 GMT

If you’re running a Foxpro application under Vista when using Aero , you might encounter a problem when scrolling through lists, such as intellisense dropdowns, comboboxes, menus.

As you move from one item in the list to the next, each item in turn appears to be selected (colors inverted), which means the prior selected item should be unselected.

However, on Vista Aero, sometimes the prior items do not get painted unselected, thus showing multiple selected items.

There’s a simple workaround (that works back to VFP7): call the GdiSetBatchLimit API.

The GdiSetBatchLimit function sets the maximum number of function calls that can be accumulated in the calling thread's current batch. The system flushes the current batch whenever this limit is exceeded.

This will be fixed in the next SP release of VFP

The workaround is to run these 2 lines of code somewhere in your application only once.

DECLARE integer GdiSetBatchLimit IN WIN32API integer

GdiSetBatchLimit(1)

Add a manifest to control your application Vista UAC behavior

Calvin_Hsia — Sat, 14 Apr 2007 00:29:00 GMT

Try this on Windows XP or Vista (I don’t remember if manifests are allowed on Win2000: can someone confirm please? Thanks)

Start Notepad, then choose File->Open and navigate to c:\windows\system32\notepad.exe and click Open.

Hit Ctrl-F to find the text “assembly”

You’ve now found the embedded XML manifest file.

Try the same with VFP9.EXE, then an EXE that you have built with VFP9

On XP, this manifest can specify additional dependencies. For VFP9, it indicates which version of Windows Common Controls to use. For an EXE that VFP built the manifest is the same as VFPs.

On Vista, this manifest can further specify security requirements for an application.

For example, on Vista, applications are not allowed to write into “Program Files” or Windows directories. Similarly with the registry. Some applications will attempt to write these.

If there is no requestedExecutionLevel, then the registry and file virtualization will be turned on. The program “thinks” it’s writing to “Program Files”, but it’s really writing to C:\Users\<username>\AppData\Local\VirtualStore\Program Files. The registry redirects HKEY_LOCAL_MACHINE\Software to HKEY_CURRENT_USER\Software\Classes\VirtualStore\MACHINE\SOFTWARE\<Application Registry Keys>

You can further control Vista UAC settings by running secpol.msc and navigating to Local Security Settings->Local Policies->Security Options

Try this on Vista: Start->Run->Cmd. Try to write a file to Program Files or Windows directories-> “Access Denied”

The MT.EXE tool that ships with Visual Studio or the Vista SDK can allow you to embed a manifest as a Windows Resource in an EXE file. Historically, only a Linker could build and manipulate a Windows Resource. Starting with Windows NT, the resources could be manipulated from within a program using the BeginUpdateResource family of functions.

Foxpro EXE files have been built the same way for about 18 years: using a Fox resource architecture. There is a stub loader, and 0 or more sections (such as the .APP) physically appended to the file. Windows tools that manipulate the EXE file format do not pay attention to any data appended to an EXE file, so when these tools write out the result, they do not write out any additional data. With no APP, the loader merely puts up a File->Open dialog requesting an APP to run.

These Windows Tools use the BeginUpdateResource family of functions, but Foxpro could not, because it still had to run on Windows 95 as well as NT

Starting with VFP8 (I think) VFP was able to add a generated Type Library as a Windows Resource inside a DLL, using the BeginUpdateResource functions. Now you know why this feature doesn’t work on Win 95.

Start Task Manager on Windows Vista, choose the Processes tab, choose View->Select Columns->Virtualization.

You will see that some processes have virtualization Enabled, Disabled, or nothing at all (depending on the privileges of the launcher) in that column.

Save this code as TestVista.Prg and run it

IF _vfp.StartMode>0 && If we're running as an EXE

MESSAGEBOX("Look at Task Pane Virtualization column for TestVista")

RETURN

ENDIF

BUILD PROJECT TestVista FROM TestVista

BUILD EXE TestVista FROM TestVista

!/n TestVista

RETURN

It builds an EXE that will show a MessageBox and then runs it. With the MessageBox showing, look at the Task Manager. The Virtualization is Enabled.

Now run this line from a VS Command prompt (Start->All Programs->Microsoft Visual Studio->Visual Studio Tools->VS Command prompt) in the same directory

mt -manifest TestVista.Exe.Manifest -outputresource: TestVista.exe;#1

Then run the TestVista.Exe. The Open File dialog shows up requesting an APP to run. Now the Virtualization is blank.

The sample below shows how to create a simple project hook that allows you to embed any file as a manifest. Try running it on Vista, with various values of requestedExecutionLevel.

For more about Vista User Account Control and manifests, see

· Registry Virtualization

· http://download.microsoft.com/download/5/6/a/56a0ed11-e073-42f9-932b-38acd478f46d/WindowsVistaUACDevReqs.doc

· The Windows Vista Developer Story: Windows Vista Application Development Requirements for User Account Control (UAC)

· Manifest Resources

· Creating a Manifest for Your Application

· For another example of project hooks and modifying the VFP built EXE/DLL, see Calvin Hsia's WebLog : Strongly typed methods and properties

(Another way to see a manifest: Using Visual Studio, you can chose File->Open->File to open an Executable. The default is to open it with the Resource Editor.

There’s a little down arrow that you can choose on the File->Open dialog so that you can choose to open the file using a different tool, such as the Binary Editor.

In the resource view, you can see the Manifest file of an executable.)

The sample code below creates a manifest and creates a project hook that will embed a manifest file

CLEAR

IF _vfp.StartMode>0 && If we're running as an EXE

MESSAGEBOX("Look at Task Pane Virtualization column for TestVista")

RETURN

ENDIF

MODIFY COMMAND PROGRAM() nowait

#if .t.

BUILD PROJECT TestVista FROM TestVista

BUILD EXE TestVista FROM TestVista

!/n TestVista

RETURN

#endif

CLEAR ALL

CLEAR

IF LOWER(JUSTFNAME(PROGRAM()))!="testvista"

?"This sample file must be called TestVista"

RETURN

ENDIF

#if .f.

To use with your project, you only need the projecthook class

#endif

SET SAFETY off

IF FILE("TestVista.Exe")

DELETE FILE TestVista.Exe

ENDIF

fAddManifest=.t.

IF !FILE("TestVista.pjx")

BUILD PROJECT TestVista FROM TestVista

ENDIF

MODIFY PROJECT TestVista NOWAIT

IF fAddManifest

*cExLevel="highestAvailable"

cExLevel="asInvoker"

* cExLevel="requireAdministrator"

TEXT TO cXML TEXTMERGE

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

</requestedPrivileges>

</security>

</trustInfo>

<assemblyIdentity

type="win32"

name="Microsoft.Windows.Common-Controls"

version="6.0.0.0"

language="*"

processorArchitecture="x86"

publicKeyToken="6595b64144ccf1df"

</dependentAssembly>

</dependency>

</assembly>

ENDTEXT

STRTOFILE(cXML,"TestVista.Exe.xml")

_vfp.ActiveProject.ProjectHook = NEWOBJECT('MFestPHook') && use projecthook to modify typelibrary if necessary

ENDIF

BUILD EXE TestVista FROM TestVista

_vfp.ActiveProject.Close

*Now test it. Try running it from Windows Explorer or a CMD prompt

!/n TestVista

#define RT_MANIFEST 24 && from winuser.h

#define FOX_SIG 33536

DEFINE CLASS MFestPHook AS ProjectHook

PROCEDURE AfterBuild(nError)

IF nError=0

ExeName=JUSTSTEM(_vfp.ActiveProject.Name)+".Exe"

MFest=ExeName+".xml"

IF FILE(MFest) && if a manifest exists

strMFest=FILETOSTR(MFest) && read in the manifest into a string

DIMENSION asec[1] && preserve 2 sections of EXE

nSects=0

h=FOPEN(ExeName)

fpos=FSEEK(h,0,2) && go to EOF

FOR i = 1 TO 20

FSEEK(h,fpos-14,0)

pmt=FREAD(h,14)

sig=BITAND(CTOBIN(SUBSTR(pmt,1,2),"2sr") ,0xffff)

sz=CTOBIN(SUBSTR(pmt,11,4),"4sr")

* ?i,sz,sig,TRANSFORM(sig,"@0x")

IF sig != FOX_SIG

nSects = i-1

EXIT

ENDIF

FSEEK(h,fpos-sz,0)

DIMENSION asec[i]

asec[i]=FREAD(h,sz)

fpos = fpos - sz

ENDFOR

FCLOSE(h)

DECLARE integer BeginUpdateResource IN WIN32API string , integer

DECLARE integer EndUpdateResource IN WIN32API integer, integer

DECLARE integer UpdateResource IN WIN32API integer,integer,integer,integer, string, integer

DECLARE Integer GetLastError IN win32api

h=BeginUpdateResource(ExeName,0)

IF h =0

?"Err=",GetLastError()

ELSE

UpdateResource(h,RT_MANIFEST,1,0x409,0,0) && del existing one, if any

UpdateResource(h,RT_MANIFEST,1,0x409,strMFest+CHR(0),LEN(strMFest))

IF EndUpdateResource(h,0)=0

?"Err=",GetLastError()

ENDIF

h=FOPEN(ExeName,2)

fpos=FSEEK(h,0,2)

FOR i = 1 TO nSects

FWRITE(h,asec[i])

ENDFOR

FCLOSE(h)

ENDIF

?"Added manifest"

ENDIF

ENDDEFINE

235882

Is this a Vista bug?

Calvin_Hsia — Thu, 19 Oct 2006 21:03:00 GMT

A customer reported a crash of a VFP application while running under the new version of Windows: Vista. The customer code attempted to automate the configuration of the web server (See Automating Web Site Administration Using IIS).

Specifically, there was a scenario under which the user code calling GETOBJECT("IIS://LOCALHOST/W3SVC/1/ROOT") would crash. At the time, the app was displaying a wizard which was a Fox form with some controls on it.

So I wrote some sample code (requires IIS to be installed on WinXP, and IIS with IIS 6 Metabase compatibility on Vista, as well as “Run As Administrator”) to try to reproduce the bug on Vista.

CLEAR

FOR i = 1 TO 10000

x=GETOBJECT("IIS://LOCALHOST/W3SVC/1/ROOT")

?i,x.defaultdoc

x=0

ENDFOR

Of course this worked flawlessly, so the customer sent me a zip file with a VFP runtime EXE that I could run on Vista to reproduce the error. Sure enough I could reproduce the crash. However, no crash occurred when the GETOBJECT line was single stepped under the VFP debugger.

Vista is shipping soon, so I need to figure out fast if this was a Vista bug.

After some debugging, I found why it was crashing. A ListBox on the form had the ColumnCount property set to 2, indicating to VFP that there should be 2 columns displayed. However, there was only one column defined in the RowSource property. In this case VFP wasn’t doing the right thing. Simple fix on the customer side: only one column was desired, so set the ColumnCount to 1. Simple fix on the VFP side: handle the case when the ColumnCount doesn’t match the number of items in the RowSource.

I came up with some code that repros the scenario in WinXP below. If you have 2 items in the RowSource, then it works fine. If not, it causes random behavior. In my case, I get “Variable '' is not found.”

Details: internally VFP maintains an Instruction Pointer (IP) that points to the next user code to execute. When executing the GETOBJECT line, it points to the code for that line. When evaluating a RowSource, the RowSource is compiled and the IP is pointed to the compiled code temporarily, then restored. The restoration was not happening if the number of items in the RowSource didn’t match the ColumnCount.

The reason it occurred on Vista was probably because WM_PAINT messages were sent to VFP to repaint the listbox while the GETOBJECT was executing. Perhaps the GETOBJECT was doing some waiting, which would cause some thread switches and idle time, allowing apps to paint. The IP was pointing at GETOBJECT, then the WM_PAINT caused the IP to point to some temporary place, then when the GETOBJECT was done, the IP was pointing at some random place to execute.

CLOSE DATABASES all

PUBLIC ox

ox=CREATEOBJECT("test")

DEFINE CLASS test as Form

left=200

AllowOutput=.f.

ADD OBJECT lst as ListBox

ADD OBJECT tmr as timer WITH interval=1000,enabled=.t.

PROCEDURE Load

CREATE CURSOR customer (Company c(10))

INSERT INTO customer VALUES ("One")

INSERT INTO customer VALUES ("Two")

PROCEDURE init

WITH this.lst as ListBox

.Width=300

.RowSourceType=2 && Alias

.RowSource="Customer.company+' asdf ' " && notice only 1 expression

* .RowSource="Customer.company+' asdf ',4 " && This is valid

.columncount=2

ENDWITH

this.show

PROCEDURE tmr.timer

?PROGRAM()

y=NEWOBJECT("form")

y.visible=1

y.windowstate=2

y=0

x=GETOBJECT("IIS://LOCALHOST/W3SVC/1/ROOT")

INKEY(.1)

ENDDEFINE