First of all, I found the JAVA code on the net, but I'm having a bit of trouble implementing it in B4J.
Following Cableguy message
Hi guys... I need to send a message to a Form Handler, basically "intercepting" the WM_NCHITTEST Message ( This allows your custom maximize button to be registered as the standard one) and Return HTMAXBUTTON (thus making the OS believe my custom Maximize button is the Native one). Getting the...
www.b4x.com
I coded this.
[CODE lang="b4x" title="Recover HWND"]'This procedure works well to recover the HWND
Private Sub GetHWND
Dim user32 As JavaObject
user32 = user32.InitializeStatic("com.sun.jna.platform.win32.User32").GetField("INSTANCE")
Dim hwnd As JavaObject = user32.RunMethod("GetActiveWindow",Null)
Log("hwnd : "&hwnd)
' Access the pointer
Dim pointer As JavaObject = hwnd.RunMethod("getPointer", Null)
' Extract the value from the pointer with NativeValue()
Dim native As JavaObject
native.InitializeStatic("com.sun.jna.Pointer")
Dim hwndLong As Long = native.RunMethod("nativeValue", Array(pointer))
Log("HWND (Long) : " & hwndLong)
If hwndLong > 0 Then
HookWindowProcedure(hwndLong)
Else
Log("Error: Invalid HWND")
End If
End Sub[/CODE]
How to intercept WM_NCHITTEST message and return HTMAXBUTTON in B4J with JNA
I have a sample code in Java to adapt to B4J.
[CODE lang="b4x" title="Java"]import com.sun.jna.platform.win32.User32;
import com.sun.jna.platform.win32.WinDef.*;
import com.sun.jna.platform.win32.WinUser.*;
import com.sun.jna.Callback;
public class MonWndProc implements Callback {
public LRESULT callback(HWND hwnd, int uMsg, WPARAM wParam, LPARAM lParam) {
if (uMsg == WinUser.WM_NCHITTEST) {
return new LRESULT(WinUser.HTMAXBUTTON); // Indique que le bouton max est actif
}
return User32.INSTANCE.DefWindowProc(hwnd, uMsg, wParam, lParam);
}
}[/CODE]
Adaptation in B4J.
[CODE lang="b4x" title="B4J"]Sub HookWindowProcedure(hwnd As Long)
Dim User32 As JavaObject
User32.InitializeStatic("com.sun.jna.platform.win32.User32")
Dim WndProc As JavaObject
WndProc.InitializeNewInstance("MonWndProc", Null) ' <-- What is the classname
User32.RunMethod("SetWindowLongPtr", Array(hwnd, -4, WndProc))
End Sub[/CODE]
MyWndProc is a class that implements Callback and intercepts WM_NCHITTEST.
SetWindowLongPtr overrides the window procedure to use MyWndProc.
HTMAXBUTTON tricks Windows into thinking the custom button is the native maximize button.
What is the classname ?
And finally.
[CODE lang="b4x" title="B4J"]Sub CustomWndProc(hwnd As String, uMsg As Int, wParam As Long, lParam As Long) As Long
If uMsg = 132 Then ' WM_NCHITTEST
Return 9 ' HTMAXBUTTON
End If
Dim User32 As JavaObject
User32.InitializeStatic("com.sun.jna.platform.win32.User32")
Return User32.RunMethod("DefWindowProc", Array(hwnd, uMsg, wParam, lParam))
End Sub[/CODE]
Here are the Logs
[CODE lang="b4x" title="Log"]WARNING: package com.sun.javafx.embed.swing.oldimpl not in javafx.swing
Waiting for debugger to connect...
Program started.
hwnd1 : (HWND) native@0xbc0568
HWND (Long) : 12322152
Error occurred on line: 50 (Main)
java.lang.ClassNotFoundException: java$lang$MonWndProc
at anywheresoftware.b4j.object.JavaObject.getCorrectClassName(JavaObject.java:289)
at anywheresoftware.b4j.object.JavaObject.InitializeNewInstance(JavaObject.java:84)
at b4j.example.main._hookwindowprocedure(main.java:144)
at b4j.example.main._appstart(main.java:114)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:629)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:237)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:167)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:111)
at anywheresoftware.b4a.shell.ShellBA.raiseEvent2(ShellBA.java:100)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:98)
at b4j.example.main.start(main.java:38)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:847)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:484)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:457)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:456)
at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:184)
at java.base/java.lang.Thread.run(Thread.java:1589)[/CODE]
Thank you for any help you can give me
