window icon support for win32 api backend

src/dlangui/graphics/drawbuf.d

@@ -830,10 +830,16 @@ class ColorDrawBuf : ColorDrawBufBase {
 	/// create copy of ColorDrawBuf
 	this(ColorDrawBuf v) {
 		this(v.width, v.height);
-		_buf.length = v._buf.length;
+		//_buf.length = v._buf.length;
 		for (int i = 0; i < _buf.length; i++)
 			_buf[i] = v._buf[i];
 	}
+	/// create resized copy of ColorDrawBuf
+	this(ColorDrawBuf v, int dx, int dy) {
+		this(dx, dy);
+        fill(0xFFFFFFFF);
+        drawRescaled(Rect(0, 0, dx, dy), v, Rect(0, 0, v.width, v.height));
+	}
 	void invertAlpha() {
 		foreach(pixel; _buf)
 			pixel ^= 0xFF000000;

src/dlangui/platforms/windows/win32drawbuf.d

@@ -11,8 +11,62 @@ class Win32ColorDrawBuf : ColorDrawBufBase {
     HDC _drawdc;
     HBITMAP _drawbmp;
     @property HDC dc() { return _drawdc; }
+    @property HBITMAP bmp() { return _drawdc; }
     this(int width, int height) {
         resize(width, height);
+    }
+	/// create resized copy of ColorDrawBuf
+	this(ColorDrawBuf v, int dx, int dy) {
+		this(dx, dy);
+        fill(0xFFFFFFFF);
+        if (_dx == dx && _dy == dy)
+            drawImage(0, 0, v);
+        else
+            drawRescaled(Rect(0, 0, dx, dy), v, Rect(0, 0, v.width, v.height));
+	}
+	void invertAlpha() {
+		for(int i = _dx * _dy - 1; i >= 0; i--)
+			_pixels[i] ^= 0xFF000000;
+	}
+    /// returns HBITMAP for alpha
+    HBITMAP createTransparencyBitmap() {
+        int hbytes = (((_dx + 7) / 8) + 1) & 0xFFFFFFFE;
+        static ubyte[] buf;
+        buf.length = hbytes * _dy * 2;
+        //for (int y = 0; y < _dy; y++) {
+        //    uint * src = scanLine(y);
+        //    ubyte * dst1 = buf.ptr + (_dy - 1 - y) * hbytes;
+        //    ubyte * dst2 = buf.ptr + (_dy - 1 - y) * hbytes + hbytes * _dy;
+        //    for (int x = 0; x < _dx; x++) {
+        //        ubyte pixel1 = 0x80; //(src[x] >> 24) > 0x80 ? 0 : 0x80;
+        //        ubyte pixel2 = (src[x] >> 24) < 0x80 ? 0 : 0x80;
+        //        int xi = x >> 3;
+        //        dst1[xi] |= (pixel1 >> (x & 7));
+        //        dst2[xi] |= (pixel2 >> (x & 7));
+        //    }
+        //}
+        // debug
+        for(int i = 0; i < hbytes * _dy; i++)
+            buf[i] = 0xFF;
+        for(int i = hbytes * _dy; i < buf.length; i++)
+            buf[i] = 0; //0xFF;
+
+        BITMAP b;
+        b.bmWidth = _dx;
+        b.bmHeight = _dy;
+        b.bmWidthBytes = hbytes;
+        b.bmPlanes = 1;
+        b.bmBitsPixel = 1;
+        b.bmBits = buf.ptr;
+        return CreateBitmapIndirect(&b);
+        //return CreateBitmap(_dx, _dy, 1, 1, buf.ptr);
+    }
+    /// destroy object, but leave bitmap as is
+    HBITMAP destoryLeavingBitmap() {
+        HBITMAP res = _drawbmp;
+        _drawbmp = null;
+        destroy(this);
+        return res;
     }
     override uint * scanLine(int y) {
         if (y >= 0 && y < _dy)
@@ -23,8 +77,10 @@ class Win32ColorDrawBuf : ColorDrawBufBase {
         clear();
     }
     override void clear() {
-        if (_drawbmp !is null) {
+        if (_drawbmp !is null || _drawdc !is null) {
+            if (_drawbmp)
                 DeleteObject(_drawbmp);
+            if (_drawdc)
                 DeleteObject(_drawdc);
             _drawbmp = null;
             _drawdc = null;

src/dlangui/platforms/windows/winapp.d

@@ -325,16 +325,38 @@ class Win32Window : Window {
 		_platform.closeWindow(this);
 	}
 
+    HICON _icon;
+
 	/// sets window icon
 	@property override void windowIcon(DrawBufRef buf) {
+        if (_icon)
+            DestroyIcon(_icon);
+        _icon = null;
 		ColorDrawBuf icon = cast(ColorDrawBuf)buf.get;
 		if (!icon) {
 			Log.e("Trying to set null icon for window");
 			return;
 		}
-		//icon = new ColorDrawBuf(icon);
-		//icon.invertAlpha();
-		//destroy(icon);
+        Win32ColorDrawBuf resizedicon = new Win32ColorDrawBuf(icon, 32, 32);
+        resizedicon.invertAlpha();
+        ICONINFO ii;
+        HBITMAP mask = resizedicon.createTransparencyBitmap();
+        HBITMAP color = resizedicon.destoryLeavingBitmap();
+        ii.fIcon = TRUE;
+        ii.xHotspot = 0;
+        ii.yHotspot = 0;
+        ii.hbmMask = mask;
+        ii.hbmColor = color;
+        _icon = CreateIconIndirect(&ii);
+        if (_icon) {
+            SendMessage(_hwnd, WM_SETICON, ICON_SMALL, cast(int)_icon);
+            SendMessage(_hwnd, WM_SETICON, ICON_BIG, cast(int)_icon);
+        } else {
+            Log.e("failed to create icon");
+        }
+        if (mask)
+            DeleteObject(mask);
+        DeleteObject(color);
 	}
 
     private void paintUsingGDI() {