Bug 1232 - NEWT Translucent Decorated Windows Not Working On Windows >= 8 (Lack of Aero / Blur )

Adopting new undocumented user32.dll Windows >= 8 API:
  - SetWindowCompositionAttribute / AccentState

See:
  - <https://github.com/riverar/sample-win10-aeroglass/blob/master/MainWindow.xaml.cs>
  - <http://withinrafael.com/adding-the-aero-glass-blur-to-your-windows-10-apps/>
  - <http://undoc.airesoft.co.uk/user32.dll/SetWindowCompositionAttribute.php>
  - <http://undoc.airesoft.co.uk/user32.dll/GetWindowCompositionAttribute.php>

+++

Cleaning up WindowsDWM.h, use on header file (in stub_includes)
for GlueGen and implementation.

+++

Merge java implementation within GDIUtil.DwmSetupTranslucency(..),
to be utilized by NEWT and JOGL.

NEWT issues GDIUtil.DwmSetupTranslucency(..) at creation
and when toggling decoration.

Toggling decoration on Win >= 8 leads to lost of translucency
when returning to decorated window.
On Win 7, this may work .. but is also buggy.

+++

Followup patch is needed for NEWT to _not_ clear the background!

1 files changed, 78 insertions, 1 deletions

diff --git a/src/nativewindow/classes/jogamp/nativewindow/windows/GDIUtil.java b/src/nativewindow/classes/jogamp/nativewindow/windows/GDIUtil.java
index 7c01d7b2e..c0f277f09 100644
--- a/src/nativewindow/classes/jogamp/nativewindow/windows/GDIUtil.java
+++ b/src/nativewindow/classes/jogamp/nativewindow/windows/GDIUtil.java
@@ -128,7 +128,13 @@ public class GDIUtil implements ToolkitProperties {
      * Windows >= 8, even if not manifested
      * @see https://msdn.microsoft.com/en-us/library/windows/desktop/ms724832%28v=vs.85%29.aspx
      */
-    private static final VersionNumber Win8Version = new VersionNumber(6, 2, 0);
+    public static final VersionNumber Win8Version = new VersionNumber(6, 2, 0);
+
+    /**
+     * Windows >= 10, manifested
+     * @see https://msdn.microsoft.com/en-us/library/windows/desktop/ms724832%28v=vs.85%29.aspx
+     */
+    public static final VersionNumber Win10Version = new VersionNumber(10, 0, 0);
 
     /**
      * Wrapper for {@link GDI#DwmIsCompositionEnabled()}
@@ -148,6 +154,77 @@ public class GDIUtil implements ToolkitProperties {
         }
     }
 
+    public static boolean DwmSetupTranslucency(final long hwnd, final boolean enable) {
+        if( !GDI.DwmIsExtensionAvailable() ) {
+            if(DEBUG) {
+                System.err.println("GDIUtil.DwmSetupTranslucency on wnd 0x"+Long.toHexString(hwnd)+": enable "+enable+" -> failed, extension not available");
+            }
+            return !enable;
+        }
+        final VersionNumber winVer = Platform.getOSVersionNumber();
+        final boolean isWin8 = winVer.compareTo(Win8Version) >= 0;
+        if( !isWin8 && !GDI.DwmIsCompositionEnabled() ) {
+            if(DEBUG) {
+                System.err.println("GDIUtil.DwmSetupTranslucency on wnd 0x"+Long.toHexString(hwnd)+": enable "+enable+" -> failed, composition disabled");
+            }
+            return !enable;
+        }
+        final boolean hasWinCompEXT = GDI.IsWindowCompositionExtensionAvailable();
+        final boolean useWinCompEXT = isWin8 && hasWinCompEXT;
+        final boolean isUndecorated = IsUndecorated(hwnd);
+        boolean ok;
+        if( useWinCompEXT && !isUndecorated ) {
+            final AccentPolicy accentPolicy = AccentPolicy.create();
+            if( enable ) {
+                // For undecorated windows, this would also enable the Glass effect!
+                accentPolicy.setAccentState(GDI.ACCENT_ENABLE_BLURBEHIND);
+            } else {
+                accentPolicy.setAccentState(GDI.ACCENT_DISABLED);
+            }
+            ok = GDI.SetWindowCompositionAccentPolicy(hwnd, accentPolicy);
+        } else {
+            // Works even for >= Win8, if undecorated
+            final DWM_BLURBEHIND bb = DWM_BLURBEHIND.create();
+            final int dwFlags = enable ? GDI.DWM_BB_ENABLE | GDI.DWM_BB_BLURREGION | GDI.DWM_BB_TRANSITIONONMAXIMIZED : GDI.DWM_BB_ENABLE;
+            // final int dwFlags = GDI.DWM_BB_ENABLE;
+            bb.setDwFlags( dwFlags );
+            bb.setFEnable( enable ? 1 : 0 );
+            bb.setHRgnBlur(0);
+            bb.setFTransitionOnMaximized(1);
+            ok = GDI.DwmEnableBlurBehindWindow(hwnd, bb);
+            if( ok ) {
+                final MARGINS m = MARGINS.create();
+                m.setCxLeftWidth(-1);
+                m.setCxRightWidth(-1);
+                m.setCyBottomHeight(-1);
+                m.setCyTopHeight(-1);
+                ok = GDI.DwmExtendFrameIntoClientArea(hwnd, m);
+            }
+        }
+        /***
+         * Not required ..
+         *
+        if( ok && isWin8 && !isUndecorated ) {
+            final IntBuffer pvAttribute = Buffers.newDirectIntBuffer(1);
+            if( enable ) {
+                // Glass Effect even if undecorated, hence not truly 100% translucent!
+                pvAttribute.put(0, GDI.DWMNCRP_ENABLED);
+            } else {
+                pvAttribute.put(0, GDI.DWMNCRP_DISABLED);
+            }
+            final int err = GDI.DwmSetWindowAttribute(hwnd, GDI.DWMWA_NCRENDERING_POLICY,
+                                                      pvAttribute,
+                                                      Buffers.sizeOfBufferElem(pvAttribute)*pvAttribute.capacity());
+            ok = 0 == err; // S_OK
+        } */
+        if(DEBUG) {
+            final boolean isChild = IsChild(hwnd);
+            System.err.println("GDIUtil.DwmSetupTranslucency on wnd 0x"+Long.toHexString(hwnd)+": enable "+enable+", isUndecorated "+isUndecorated+", isChild "+isChild+
+                               ", version "+winVer+", isWin8 "+isWin8+", hasWinCompEXT "+hasWinCompEXT+", useWinCompEXT "+useWinCompEXT+" -> ok: "+ok);
+        }
+        return ok;
+    }
+
     public static boolean IsUndecorated(final long win) {
         return IsUndecorated0(win);
     }