Merge branch 'windows_icon_in_bytes' #310 #135

tonsky · tonsky · commit 8d67d734448c · 2026-06-28T23:57:02.000+02:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,6 +1,7 @@
 # WIP
 
 - Bumped types in pom.xml to 0.2.0
+- Windows, Linux: Window::setIconPixels (previously setIconData on Linux) #310 #135 via @chirontt 
 
 # 0.4.25 - Jun 16, 2026
 
diff --git a/examples/dashboard/java/Example.java b/examples/dashboard/java/Example.java
@@ -42,6 +42,19 @@ public class Example implements Consumer<Event> {
 
     public Options progressBars = new Options("Default", "0%", "50%", "100%", "Indeterminate");
 
+    // Icons to cycle through with Ctrl+I. .ico/.icns are loaded as files, .png as raw image data.
+    public Options icons = switch (Platform.CURRENT) {
+        case WINDOWS -> new Options("examples/dashboard/resources/windows.ico",
+                                    "windows/icon_16x16.png",
+                                    "windows/icon_24x24.png",
+                                    "windows/icon_32x32.png",
+                                    "windows/icon_48x48.png",
+                                    "windows/icon_256x256.png");
+        case MACOS   -> new Options("examples/dashboard/resources/macos.icns");
+        case X11     -> new Options("linux/icon_24x24.png",
+                                    "linux/icon_48x48.png");
+    };
+
     public Example() {
         window = App.makeWindow();
         window.setEventListener(this);
@@ -54,7 +67,7 @@ public Example() {
         panelMouseCursors = new PanelMouseCursors(window);
         panelRendering = new PanelRendering(window);
         panelEvents = new PanelEvents(window);
-        panelTheme = new PanelTheme(window);
+        panelTheme = new PanelTheme(window, icons);
         panelTouch = new PanelTouch(window);
 
         var scale = window.getScreen().getScale();
@@ -79,26 +92,11 @@ public Example() {
             case 4 -> window.setWindowPosition(bounds.getLeft() + bounds.getWidth() / 2, bounds.getTop() + bounds.getHeight() / 2);
         }
 
-        var classLoader = getClass().getClassLoader();
-        switch (Platform.CURRENT) {
-            case WINDOWS -> {
-                window.setIcon(new File("examples/dashboard/resources/windows.ico"));
-            }
-            case MACOS -> {
-                window.setIcon(new File("examples/dashboard/resources/macos.icns"));
-            }
-            case X11 -> {
-                ((WindowX11) window).setClassHint("jwm-dashboard-example"); // allows OS-wide identification of the window (e.g. icon themes, .desktop files)
-                try (var in = classLoader.getResourceAsStream("linux/icon_48x48.png")) {
-                    Bitmap i = Bitmap.makeFromImage(Image.makeDeferredFromEncodedBytes(in.readAllBytes()));
-                    ImageInfo info = i.getImageInfo();
-
-                    ((WindowX11) window).setIconData(info.getWidth(), info.getHeight(), i.readPixels());
-                } catch (IOException e) {
-                    e.printStackTrace();
-                }
-            }
+        if (window instanceof WindowX11 windowX11) {
+            // allows OS-wide identification of the window (e.g. icon themes, .desktop files)
+            windowX11.setClassHint("jwm-dashboard-example");
         }
+        applyIcon();
 
         window.setVisible(true);
         initialized = true;
@@ -215,6 +213,10 @@ public void accept(Event e) {
                         window.minimize();
                     case B ->
                         setProgressBar(progressBars.next());
+                    case I -> {
+                        icons.next();
+                        applyIcon();
+                    }
                     case A -> {
                         if (window instanceof WindowMac windowMac) {
                             boolean enabled = !windowMac.isPressAndHoldEnabled();
@@ -235,6 +237,23 @@ public void accept(Event e) {
         }
     }
 
+    public void applyIcon() {
+        String path = icons.get();
+        if (path.endsWith(".png")) {
+            try (var in = getClass().getClassLoader().getResourceAsStream(path);
+                 var img = Image.makeDeferredFromEncodedBytes(in.readAllBytes());
+                 var bitmap = Bitmap.makeFromImage(img); ) 
+            {
+                ImageInfo info = bitmap.getImageInfo();
+                window.setIconPixels(info.getWidth(), info.getHeight(), bitmap.readPixels());
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        } else {
+            window.setIcon(new File(path));
+        }
+    }
+
     public void setProgressBar(String type) {
         progressBars.set(type);
         window.setProgressBar(switch (type) {
diff --git a/examples/dashboard/java/PanelLegend.java b/examples/dashboard/java/PanelLegend.java
@@ -22,6 +22,7 @@ public PanelLegend(Window window) {
         shortcuts.put("U", "Lock mouse cursor");
         shortcuts.put("Z", "Toggle Z-order");
         shortcuts.put("B", "Toggle Progress Bar");
+        shortcuts.put("I", "Toggle icon");
         shortcuts.put("O", "Opacity");
         shortcuts.put("1", "Minimize");
         shortcuts.put("2", "Maximize");
diff --git a/examples/dashboard/java/PanelTheme.java b/examples/dashboard/java/PanelTheme.java
@@ -5,9 +5,11 @@
 import io.github.humbleui.skija.*;
 
 public class PanelTheme extends Panel {
+    public Options icons;
 
-    public PanelTheme(Window window) {
+    public PanelTheme(Window window, Options icons) {
         super(window);
+        this.icons = icons;
     }
 
     @Override
@@ -60,6 +62,11 @@ public void paintImpl(Canvas canvas, int width, int height, float scale) {
 
             canvas.drawString("zOrder", Example.PADDING, Example.PADDING * 12, Example.FONT12, paint);
             canvas.drawString("" + window.getZOrder(), width / 2 + Example.PADDING / 2, Example.PADDING * 12, Example.FONT12, paint);
+
+            String icon = icons.get();
+            icon = icon.substring(icon.lastIndexOf('/') + 1);
+            canvas.drawString("icon", Example.PADDING, Example.PADDING * 14, Example.FONT12, paint);
+            canvas.drawString(icon, width / 2 + Example.PADDING / 2, Example.PADDING * 14, Example.FONT12, paint);
         }
     }
 }
diff --git a/linux/cc/WindowX11.cc b/linux/cc/WindowX11.cc
@@ -42,7 +42,7 @@ void WindowX11::setClass(const std::string& name, const std::string& appClass) {
     }
 }
 
-void WindowX11::setIconData(int width, int height, const unsigned char* argb) {
+void WindowX11::setIconPixels(int width, int height, const unsigned char* argb) {
     size_t size = width * height;
     size_t count = size + 2;
     std::unique_ptr<long[]> buffer{new long[count]};
@@ -609,13 +609,12 @@ extern "C" JNIEXPORT void JNICALL Java_io_github_humbleui_jwm_WindowX11__1nSetCl
     instance->setClass(bytesToString(env, name), bytesToString(env, appClass));
 }
 
-extern "C" JNIEXPORT void JNICALL Java_io_github_humbleui_jwm_WindowX11__1nSetIconData
-        (JNIEnv* env, jobject obj, jint width, jint height, jbyteArray data) {
+extern "C" JNIEXPORT void JNICALL Java_io_github_humbleui_jwm_WindowX11__1nSetIconPixels
+        (JNIEnv* env, jobject obj, jint width, jint height, jbyteArray pixelsArr) {
     jwm::WindowX11* instance = reinterpret_cast<jwm::WindowX11*>(jwm::classes::Native::fromJava(env, obj));
-
-    jbyte* bytes = env->GetByteArrayElements(data, nullptr);
-    instance->setIconData(width, height, reinterpret_cast<const unsigned char*>(bytes));
-    env->ReleaseByteArrayElements(data, bytes, 0);
+    jbyte* pixels = env->GetByteArrayElements(pixelsArr, nullptr);
+    instance->setIconPixels(width, height, reinterpret_cast<const unsigned char*>(pixels));
+    env->ReleaseByteArrayElements(pixelsArr, pixels, 0);
 }
 
 extern "C" JNIEXPORT void JNICALL Java_io_github_humbleui_jwm_WindowX11__1nSetTitlebarVisible
diff --git a/linux/cc/WindowX11.hh b/linux/cc/WindowX11.hh
@@ -39,7 +39,7 @@ namespace jwm {
         }
         void setTitle(const std::string& title);
         void setClass(const std::string& name, const std::string& class_);
-        void setIconData(int width, int height, const unsigned char* argb);
+        void setIconPixels(int width, int height, const unsigned char* argb);
         void setTitlebarVisible(bool isVisible);
 
         void maximize();
diff --git a/linux/java/WindowX11.java b/linux/java/WindowX11.java
@@ -98,18 +98,19 @@ public Window setClassHint(String name, String appClass) {
     /**
      * <p>Set window icon from raw image bytes.</p>
      *
-     * <p>{@code data} must have a length of {@code width * height * 4}, representing per-pixel ARGB data.</p>
+     * <p>{@code pixels} must have a length of {@code width * height * 4}, representing per-pixel ARGB data.</p>
      *
-     * @param width     icon width in pixels
-     * @param height    icon height in pixels
-     * @param data      icon image data
-     * @return          this
+     * @param width   icon width in pixels
+     * @param height  icon height in pixels
+     * @param pixels  icon image data
+     * @return        this
      */
+    @Override
     @NotNull @Contract("-> this")
-    public Window setIconData(int width, int height, byte[] data) {
+    public Window setIconPixels(int width, int height, byte[] pixels) {
         assert _onUIThread() : "Should be run on UI thread";
-        assert data.length == width*height*4 : "Incorrect icon data array length";
-        _nSetIconData(width, height, data);
+        assert pixels.length == width * height * 4 : "Incorrect icon data array length";
+        _nSetIconPixels(width, height, pixels);
         return this;
     }
 
@@ -264,7 +265,7 @@ public boolean isFullScreen() {
     @ApiStatus.Internal public native void _nRestore();
     @ApiStatus.Internal public native void _nSetTitle(byte[] title);
     @ApiStatus.Internal public native void _nSetClassHint(byte[] name, byte[] appClass);
-    @ApiStatus.Internal public native void _nSetIconData(int width, int height, byte[] data);
+    @ApiStatus.Internal public native void _nSetIconPixels(int width, int height, byte[] pixels);
     @ApiStatus.Internal public native void _nSetTitlebarVisible(boolean isVisible);
     @ApiStatus.Internal public native void _nSetFullScreen(boolean isFullScreen);
     @ApiStatus.Internal public native boolean _nIsFullScreen();
diff --git a/macos/java/WindowMac.java b/macos/java/WindowMac.java
@@ -109,6 +109,12 @@ public Window setIcon(File icon) {
         return this;
     }
 
+    @Override
+    public Window setIconPixels(int width, int height, byte[] pixels) {
+        // Not implemented
+        return this;
+    }
+
     /**
      * <p>Shortcut for {@link #setTitleVisible(boolean)}, {@link #setFullSizeContentView(boolean)}</p>
      *
diff --git a/shared/java/Window.java b/shared/java/Window.java
@@ -204,6 +204,21 @@ public IRect getContentRectAbsolute() {
     @NotNull @Contract("-> this")
     public abstract Window setIcon(File icon);
 
+    /**
+     * <p>Set window icon from raw image bytes.</p>
+     *
+     * <p>{@code pixels} must have a length of {@code width * height * 4}, representing per-pixel ARGB data.</p>
+     *
+     * <p>Displayed in the top-bar and task switcher on Linux and Windows. No-op on macOS.</p>
+     *
+     * @param width   icon width in pixels
+     * @param height  icon height in pixels
+     * @param pixels  icon image data
+     * @return        this
+     */
+    @NotNull @Contract("_, _, _ -> this")
+    public abstract Window setIconPixels(int width, int height, byte[] pixels);
+
     /**
      * <p>Completely removes the titlebar from the window including buttons and title.</p>
      *
diff --git a/windows/cc/WindowWin32.cc b/windows/cc/WindowWin32.cc
@@ -122,11 +122,81 @@ void jwm::WindowWin32::setTitlebarVisible(bool isVisible) {
                  SWP_NOZORDER | SWP_NOACTIVATE | SWP_FRAMECHANGED);
 }
 
+void jwm::WindowWin32::_setIconsInternal(HICON hSmall, HICON hBig) {
+    // Apply small icon (title bar / taskbar)
+    if (hSmall) {
+        if (_hIconSmall)
+            DestroyIcon(_hIconSmall);
+        _hIconSmall = hSmall;
+        SendMessage(_hWnd, WM_SETICON, ICON_SMALL, (LPARAM)hSmall);
+    } else {
+        JWM_VERBOSE("Failed to create small icon");
+    }
+    // Apply big icon (Alt-Tab / task switcher)
+    if (hBig) {
+        if (_hIconBig)
+            DestroyIcon(_hIconBig);
+        _hIconBig = hBig;
+        SendMessage(_hWnd, WM_SETICON, ICON_BIG, (LPARAM)hBig);
+    } else {
+        JWM_VERBOSE("Failed to create big icon");
+    }
+}
+
 void jwm::WindowWin32::setIcon(const std::wstring& iconPath) {
     JWM_VERBOSE("Set window icon '" << iconPath << "'");
-    // width / height of 0 along with LR_DEFAULTSIZE tells windows to load the default icon size.
-    HICON hicon = (HICON)LoadImage(NULL, iconPath.c_str(), IMAGE_ICON, 0, 0, LR_LOADFROMFILE | LR_DEFAULTSIZE);
-    SendMessage(_hWnd, WM_SETICON, ICON_SMALL, (LPARAM)hicon);
+    int cxS = GetSystemMetrics(SM_CXSMICON), cyS = GetSystemMetrics(SM_CYSMICON);
+    int cxB = GetSystemMetrics(SM_CXICON),   cyB = GetSystemMetrics(SM_CYICON);
+    HICON hSmall = (HICON)LoadImage(NULL, iconPath.c_str(), IMAGE_ICON, cxS, cyS, LR_LOADFROMFILE);
+    HICON hBig   = (HICON)LoadImage(NULL, iconPath.c_str(), IMAGE_ICON, cxB, cyB, LR_LOADFROMFILE);
+    _setIconsInternal(hSmall, hBig);
+}
+
+HICON jwm::WindowWin32::_createIconFromPixels(int width, int height, const unsigned char* argb) {
+    // The incoming bytes are in B, G, R, A order per pixel (matching the Linux
+    // setIconData layout), which is exactly a Windows 32bpp BGRA DIB, so we can
+    // copy them straight into a top-down DIB section.
+    BITMAPV5HEADER bi = {};
+    bi.bV5Size        = sizeof(BITMAPV5HEADER);
+    bi.bV5Width       = width;
+    bi.bV5Height      = -height; // negative -> top-down
+    bi.bV5Planes      = 1;
+    bi.bV5BitCount    = 32;
+    bi.bV5Compression = BI_BITFIELDS;
+    bi.bV5RedMask     = 0x00FF0000;
+    bi.bV5GreenMask   = 0x0000FF00;
+    bi.bV5BlueMask    = 0x000000FF;
+    bi.bV5AlphaMask   = 0xFF000000;
+
+    HDC   hdc  = GetDC(NULL);
+    void* bits = nullptr;
+    HBITMAP hbmColor = CreateDIBSection(hdc, reinterpret_cast<BITMAPINFO*>(&bi), DIB_RGB_COLORS, &bits, NULL, 0);
+    ReleaseDC(NULL, hdc);
+    if (!hbmColor || !bits)
+        return nullptr;
+    memcpy(bits, argb, static_cast<size_t>(width) * height * 4);
+
+    // Monochrome mask is required but unused for 32bpp icons (alpha is honored).
+    HBITMAP hbmMask = CreateBitmap(width, height, 1, 1, NULL);
+
+    ICONINFO ii = {};
+    ii.fIcon    = TRUE;
+    ii.hbmColor = hbmColor;
+    ii.hbmMask  = hbmMask;
+    HICON hIcon = CreateIconIndirect(&ii);
+
+    DeleteObject(hbmColor);
+    DeleteObject(hbmMask);
+    return hIcon;
+}
+
+void jwm::WindowWin32::setIconPixels(int width, int height, const unsigned char* argb) {
+    JWM_VERBOSE("Set window icon from raw image data " << width << "x" << height);
+    // A single source image is used for both icon slots; Windows scales it to
+    // the small (title bar / taskbar) and big (Alt-Tab) metrics as needed.
+    HICON hSmall = _createIconFromPixels(width, height, argb);
+    HICON hBig   = _createIconFromPixels(width, height, argb);
+    _setIconsInternal(hSmall, hBig);
 }
 
 void jwm::WindowWin32::setOpacity(float opacity) {
@@ -896,6 +966,16 @@ void jwm::WindowWin32::_destroyInternal() {
         _hMouseCursor = nullptr;
     }
 
+    if (_hIconSmall) {
+        DestroyIcon(_hIconSmall);
+        _hIconSmall = nullptr;
+    }
+
+    if (_hIconBig) {
+        DestroyIcon(_hIconBig);
+        _hIconBig = nullptr;
+    }
+
     if (_hWnd) {
         DestroyWindow(_hWnd);
         _hWnd = nullptr;
@@ -1103,6 +1183,14 @@ extern "C" JNIEXPORT void JNICALL Java_io_github_humbleui_jwm_WindowWin32__1nSet
     env->ReleaseStringChars(iconPath, iconPathStr);
 }
 
+extern "C" JNIEXPORT void JNICALL Java_io_github_humbleui_jwm_WindowWin32__1nSetIconPixels
+        (JNIEnv* env, jobject obj, jint width, jint height, jbyteArray pixelsArr) {
+    jwm::WindowWin32* instance = reinterpret_cast<jwm::WindowWin32*>(jwm::classes::Native::fromJava(env, obj));
+    jbyte* pixels = env->GetByteArrayElements(pixelsArr, nullptr);
+    instance->setIconPixels(width, height, reinterpret_cast<const unsigned char*>(pixels));
+    env->ReleaseByteArrayElements(pixelsArr, pixels, 0);
+}
+
 extern "C" JNIEXPORT void JNICALL Java_io_github_humbleui_jwm_WindowWin32__1nSetVisible
         (JNIEnv* env, jobject obj, jboolean isVisible) {
     jwm::WindowWin32* instance = reinterpret_cast<jwm::WindowWin32*>(jwm::classes::Native::fromJava(env, obj));
diff --git a/windows/cc/WindowWin32.hh b/windows/cc/WindowWin32.hh
@@ -53,6 +53,7 @@ namespace jwm {
         void setTitle(const std::wstring& title);
         void setTitlebarVisible(bool isVisible);
         void setIcon(const std::wstring& iconPath);
+        void setIconPixels(int width, int height, const unsigned char* argb);
         void setOpacity(float opacity);
         float getOpacity();
         bool isHighContrast();
@@ -98,6 +99,8 @@ namespace jwm {
         void _killFrameTimer();
         bool _createInternal(int x, int y, int w, int h, const wchar_t* caption);
         void _destroyInternal();
+        void _setIconsInternal(HICON hSmall, HICON hBig);
+        HICON _createIconFromPixels(int width, int height, const unsigned char* argb);
         void _close();
         void _setMouseCursorInternal();
         void _imeResetComposition();
@@ -120,6 +123,8 @@ namespace jwm {
         HWND _hWnd = nullptr;
         HCURSOR _hMouseCursor = nullptr;
         HCURSOR _hDefaultMouseCursor = nullptr;
+        HICON _hIconSmall = nullptr;
+        HICON _hIconBig = nullptr;
         int _lastMousePosX = 0;
         int _lastMousePosY = 0;
         bool _minimized = false;
diff --git a/windows/java/WindowWin32.java b/windows/java/WindowWin32.java

Original file line number	Diff line number	Diff line change
`@@ -5,9 +5,11 @@`
`5`	`5`	`import io.github.humbleui.skija.*;`
`6`	`6`
`7`	`7`	`public class PanelTheme extends Panel {`
	`8`	`+ public Options icons;`
`8`	`9`
`9`		`- public PanelTheme(Window window) {`
	`10`	`+ public PanelTheme(Window window, Options icons) {`
`10`	`11`	`super(window);`
	`12`	`+ this.icons = icons;`
`11`	`13`	`}`
`12`	`14`
`13`	`15`	`@Override`
`@@ -60,6 +62,11 @@ public void paintImpl(Canvas canvas, int width, int height, float scale) {`
`60`	`62`
`61`	`63`	`canvas.drawString("zOrder", Example.PADDING, Example.PADDING * 12, Example.FONT12, paint);`
`62`	`64`	`canvas.drawString("" + window.getZOrder(), width / 2 + Example.PADDING / 2, Example.PADDING * 12, Example.FONT12, paint);`
	`65`	`+`
	`66`	`+ String icon = icons.get();`
	`67`	`+ icon = icon.substring(icon.lastIndexOf('/') + 1);`
	`68`	`+ canvas.drawString("icon", Example.PADDING, Example.PADDING * 14, Example.FONT12, paint);`
	`69`	`+ canvas.drawString(icon, width / 2 + Example.PADDING / 2, Example.PADDING * 14, Example.FONT12, paint);`
`63`	`70`	`}`
`64`	`71`	`}`
`65`	`72`	`}`
Original file line number	Diff line number	Diff line change
`@@ -42,7 +42,7 @@ void WindowX11::setClass(const std::string& name, const std::string& appClass) {`
`42`	`42`	`}`
`43`	`43`	`}`
`44`	`44`
`45`		`-void WindowX11::setIconData(int width, int height, const unsigned char* argb) {`
	`45`	`+void WindowX11::setIconPixels(int width, int height, const unsigned char* argb) {`
`46`	`46`	`size_t size = width * height;`
`47`	`47`	`size_t count = size + 2;`
`48`	`48`	`std::unique_ptr<long[]> buffer{new long[count]};`
`@@ -609,13 +609,12 @@ extern "C" JNIEXPORT void JNICALL Java_io_github_humbleui_jwm_WindowX11__1nSetCl`
`609`	`609`	`instance->setClass(bytesToString(env, name), bytesToString(env, appClass));`
`610`	`610`	`}`
`611`	`611`
`612`		`-extern "C" JNIEXPORT void JNICALL Java_io_github_humbleui_jwm_WindowX11__1nSetIconData`
`613`		`- (JNIEnv* env, jobject obj, jint width, jint height, jbyteArray data) {`
	`612`	`+extern "C" JNIEXPORT void JNICALL Java_io_github_humbleui_jwm_WindowX11__1nSetIconPixels`
	`613`	`+ (JNIEnv* env, jobject obj, jint width, jint height, jbyteArray pixelsArr) {`
`614`	`614`	`jwm::WindowX11* instance = reinterpret_cast<jwm::WindowX11*>(jwm::classes::Native::fromJava(env, obj));`
`615`		`-`
`616`		`- jbyte* bytes = env->GetByteArrayElements(data, nullptr);`
`617`		`- instance->setIconData(width, height, reinterpret_cast<const unsigned char*>(bytes));`
`618`		`- env->ReleaseByteArrayElements(data, bytes, 0);`
	`615`	`+ jbyte* pixels = env->GetByteArrayElements(pixelsArr, nullptr);`
	`616`	`+ instance->setIconPixels(width, height, reinterpret_cast<const unsigned char*>(pixels));`
	`617`	`+ env->ReleaseByteArrayElements(pixelsArr, pixels, 0);`
`619`	`618`	`}`
`620`	`619`
`621`	`620`	`extern "C" JNIEXPORT void JNICALL Java_io_github_humbleui_jwm_WindowX11__1nSetTitlebarVisible`
Original file line number	Diff line number	Diff line change
`@@ -39,7 +39,7 @@ namespace jwm {`
`39`	`39`	`}`
`40`	`40`	`void setTitle(const std::string& title);`
`41`	`41`	`void setClass(const std::string& name, const std::string& class_);`
`42`		`- void setIconData(int width, int height, const unsigned char* argb);`
	`42`	`+ void setIconPixels(int width, int height, const unsigned char* argb);`
`43`	`43`	`void setTitlebarVisible(bool isVisible);`
`44`	`44`
`45`	`45`	`void maximize();`
Original file line number	Diff line number	Diff line change
`@@ -109,6 +109,12 @@ public Window setIcon(File icon) {`
`109`	`109`	`return this;`
`110`	`110`	`}`
`111`	`111`
	`112`	`+ @Override`
	`113`	`+ public Window setIconPixels(int width, int height, byte[] pixels) {`
	`114`	`+ // Not implemented`
	`115`	`+ return this;`
	`116`	`+ }`
	`117`	`+`
`112`	`118`	`/**`
`113`	`119`	`* <p>Shortcut for {@link #setTitleVisible(boolean)}, {@link #setFullSizeContentView(boolean)}</p>`
`114`	`120`	`*`