Fix bug 105043: Panels [WIN]: For minimize panels, taskbar hover preview show the 4-pixel represent…

ui/views/widget/native_widget_win.cc

Index: ui/views/widget/native_widget_win.cc
diff --git a/ui/views/widget/native_widget_win.cc b/ui/views/widget/native_widget_win.cc
index fe4c6b14e54183c5658f509c7816b1ec4a8e8f28..18c18866eff4fd1528c7f067199f4e3ebe7d49e9 100644
--- a/ui/views/widget/native_widget_win.cc
+++ b/ui/views/widget/native_widget_win.cc
@@ -28,6 +28,7 @@
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/canvas_paint.h"
 #include "ui/gfx/canvas_skia_paint.h"
+#include "ui/gfx/gdi_util.h"
 #include "ui/gfx/icon_util.h"
 #include "ui/base/native_theme/native_theme_win.h"
 #include "ui/gfx/path.h"
@@ -330,6 +331,27 @@ BOOL CALLBACK FindOwnedWindowsCallback(HWND hwnd, LPARAM param) {
   return TRUE;
 }
 
+HBITMAP GetNativeBitmapFromSkBitmap(const SkBitmap& bitmap) {
+  int width = bitmap.width();
+  int height = bitmap.height();
+
+  BITMAPV4HEADER native_bitmap_header;
+  gfx::CreateBitmapV4Header(width, height, &native_bitmap_header);
+
+  HDC dc = ::GetDC(NULL);
+  void* bits;
+  HBITMAP native_bitmap = ::CreateDIBSection(dc,
+      reinterpret_cast<BITMAPINFO*>(&native_bitmap_header),
+      DIB_RGB_COLORS,
+      &bits,
+      NULL,
+      0);
+  DCHECK(native_bitmap);
+  ::ReleaseDC(NULL, dc);
+  bitmap.copyPixelsTo(bits, width * height * 4, width * 4);
+  return native_bitmap;
+}
+
 }  // namespace
 
 // static
@@ -1367,6 +1389,50 @@ LRESULT NativeWidgetWin::OnDwmCompositionChanged(UINT msg,
   return 0;
 }
 
+LRESULT NativeWidgetWin::OnDwmSendIconicThumbnail(UINT msg,
+                                                  WPARAM w_param,
+                                                  LPARAM l_param) {
+  if (!GetWidget()->non_client_view()) {
+    SetMsgHandled(FALSE);
+    return 0;
+  }
+
+  gfx::Size size(HIWORD(l_param), LOWORD(l_param));
+  SkBitmap preview_bitmap =
+      GetWidget()->widget_delegate()->GetPreviewImage(size, false);
+  if (preview_bitmap.empty()) {
+    SetMsgHandled(FALSE);
+    return 0;
+  }
+
+  HBITMAP native_bitmap = GetNativeBitmapFromSkBitmap(preview_bitmap);
+  ::DwmSetIconicThumbnail(hwnd(), native_bitmap, 0);
+  ::DeleteObject(native_bitmap);
+  return 0;
+}
+
+LRESULT NativeWidgetWin::OnDwmSendIconicLivePreviewBitmap(UINT msg,
+                                                          WPARAM w_param,
+                                                          LPARAM l_param) {
+  if (!GetWidget()->non_client_view()) {
+    SetMsgHandled(FALSE);
+    return 0;
+  }
+
+  gfx::Rect bounds = GetWindowScreenBounds();
+  SkBitmap preview_bitmap =
+      GetWidget()->widget_delegate()->GetPreviewImage(bounds.size(), true);
+  if (preview_bitmap.empty()) {
+    SetMsgHandled(FALSE);
+    return 0;
+  }
+
+  HBITMAP native_bitmap = GetNativeBitmapFromSkBitmap(preview_bitmap);
+  ::DwmSetIconicLivePreviewBitmap(hwnd(), native_bitmap, NULL, 0);
+  ::DeleteObject(native_bitmap);
+  return 0;
+}
+
 void NativeWidgetWin::OnEndSession(BOOL ending, UINT logoff) {
   SetMsgHandled(FALSE);
 }