support window icon

examples/example1/src/main.d

@@ -469,6 +469,7 @@ extern (C) int UIAppMain(string[] args) {
 	} else {
 	    window.mainWidget = (new Button()).text("sample button");
 	}
+	window.windowIcon = drawableCache.getImage("dlangui-logo1");
     window.show();
     //window.windowCaption = "New Window Caption";
     // run message loop

src/dlangui/graphics/drawbuf.d

@@ -823,9 +823,21 @@ class GrayDrawBuf : DrawBuf {
 
 class ColorDrawBuf : ColorDrawBufBase {
     uint[] _buf;
+	/// create ARGB8888 draw buf of specified width and height
     this(int width, int height) {
         resize(width, height);
     }
+	/// create copy of ColorDrawBuf
+	this(ColorDrawBuf v) {
+		this(v.width, v.height);
+		_buf.length = v._buf.length;
+		for (int i = 0; i < _buf.length; i++)
+			_buf[i] = v._buf[i];
+	}
+	void invertAlpha() {
+		foreach(pixel; _buf)
+			pixel ^= 0xFF000000;
+	}
     override uint * scanLine(int y) {
         if (y >= 0 && y < _dy)
             return _buf.ptr + _dx * y;

src/dlangui/graphics/resources.d

@@ -886,6 +886,14 @@ class DrawableCache {
         Log.w("resource ", id, " is not found");
         return null;
     }
+	/// get image (DrawBuf) from imageCache by resource id
+	DrawBufRef getImage(string id) {
+		DrawBufRef res;
+		string fname = findResource(id);
+		if (fname.endsWith(".png") || fname.endsWith(".jpg"))
+			return imageCache.get(fname);
+		return res;
+	}
     this() {
         debug Log.i("Creating DrawableCache");
     }

src/dlangui/platforms/common/platform.d

@@ -69,6 +69,9 @@ class Window {
     abstract @property dstring windowCaption();
 	/// sets window caption
     abstract @property void windowCaption(dstring caption);
+	/// sets window icon
+	abstract @property void windowIcon(DrawBufRef icon);
+
 	/// requests layout for main widget and popups
 	void requestLayout() {
 		if (_mainWidget)

src/dlangui/platforms/sdl/sdlapp.d

@@ -87,13 +87,14 @@ version(USE_SDL) {
 		protected uint _flags;
 		bool create(uint flags) {
 			_flags = flags;
-			uint windowFlags = 0;
+			uint windowFlags = SDL_WINDOW_HIDDEN;
 			if (flags & WindowFlag.Resizable)
 				windowFlags |= SDL_WINDOW_RESIZABLE;
 			if (flags & WindowFlag.Fullscreen)
 				windowFlags |= SDL_WINDOW_FULLSCREEN;
-			if (flags & WindowFlag.Modal)
-				windowFlags |= SDL_WINDOW_INPUT_GRABBED;
+			// TODO: implement modal behavior
+			//if (flags & WindowFlag.Modal)
+			//	windowFlags |= SDL_WINDOW_INPUT_GRABBED;
 			version(USE_OPENGL) {
                 if (_enableOpengl)
                     windowFlags |= SDL_WINDOW_OPENGL;
@@ -178,6 +179,27 @@ version(USE_SDL) {
 				SDL_SetWindowTitle(_win, toUTF8(_caption).toStringz);
 		}
 
+		/// sets window icon
+		@property override void windowIcon(DrawBufRef buf) {
+			ColorDrawBuf icon = cast(ColorDrawBuf)buf.get;
+			if (!icon) {
+				Log.e("Trying to set null icon for window");
+				return;
+			}
+			icon = new ColorDrawBuf(icon);
+			icon.invertAlpha();
+			SDL_Surface *surface = SDL_CreateRGBSurfaceFrom(icon.scanLine(0), icon.width, icon.height, 32, icon.width * 4, 0x00ff0000,0x0000ff00,0x000000ff,0xff000000);
+			if (surface) {
+				// The icon is attached to the window pointer
+				SDL_SetWindowIcon(_win, surface); 
+				// ...and the surface containing the icon pixel data is no longer required.
+				SDL_FreeSurface(surface);
+			} else {
+				Log.e("failed to set window icon");
+			}
+			destroy(icon);
+		}
+
 		/// after drawing, call to schedule redraw if animation is active
 		override void scheduleAnimation() {
 			invalidate();