Add ability to generate .ico file from app icon for shortcut files

server/src/main/java/com/genymobile/scrcpy/IcoFileCreator.java

@@ -0,0 +1,145 @@
+package com.genymobile.scrcpy;
+
+import android.content.pm.PackageManager;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.drawable.Drawable;
+
+import com.genymobile.scrcpy.util.Ln;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.util.HashMap;
+import java.util.Map;
+
+public class IcoFileCreator {
+    public static void createIcoFile(String packageName) {
+        try {
+            PackageManager pm = FakeContext.get().getPackageManager();
+            Drawable appIcon = pm.getApplicationIcon(packageName);
+
+            // <https://stackoverflow.com/posts/74241508/revisions>
+            int[] sizes = {256, 128, 64, 48, 40, 32, 24, 20, 16};
+            byte[] icoData = createIcoData(appIcon, sizes);
+
+            File outputDir = new File("/data/local/tmp/ico/");
+            if (!outputDir.exists()) {
+                outputDir.mkdirs();
+            }
+            File outputFile = new File(outputDir, packageName + ".ico");
+            FileOutputStream fos = new FileOutputStream(outputFile);
+            fos.write(icoData);
+            fos.close();
+            Ln.d("ICO file saved to: " + outputFile.getAbsolutePath());
+        } catch (Exception e) {
+            Ln.e("Error creating ICO file for package: "+packageName, e);
+        }
+    }
+
+    private static byte[] createIcoData(Drawable drawable, int[] sizes) {
+        int numImages = sizes.length;
+        int totalImageDataSize = calculateImageDataSize(sizes);
+
+        ByteBuffer buffer = ByteBuffer.allocate(6 + numImages * 16 + totalImageDataSize);
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+        buffer.putShort((short) 0); // Reserved
+        buffer.putShort((short) 1); // ICO type
+        buffer.putShort((short) numImages); // Number of images
+
+        int imageDataOffset = 6 + numImages * 16;
+
+        Map<Integer, byte[]> cachedImages = new HashMap<>();
+        for (int size : sizes) {
+            Bitmap bitmap = drawableToBitmap(drawable, size, size);
+
+            byte[] imageData = bitmapToIcoImageData(bitmap);
+            cachedImages.put(size, imageData);
+
+            buffer.put((byte) size); // Width
+            buffer.put((byte) size); // Height
+            buffer.put((byte) 0); // Number of colors in palette
+            buffer.put((byte) 0); // Reserved
+            buffer.putShort((short) 1); // Color planes
+            buffer.putShort((short) 32); // Bits per pixel
+            buffer.putInt(imageData.length); // Image size
+            buffer.putInt(imageDataOffset); // Offset to image data
+
+            imageDataOffset += imageData.length;
+            bitmap.recycle();
+        }
+
+        for (int size : sizes) {
+            buffer.put(cachedImages.get(size));
+        }
+
+        return buffer.array();
+    }
+
+    private static int calculateImageDataSize(int[] sizes) {
+        int totalSize = 0;
+        for (int size : sizes) {
+            int andMaskSize = ((size + 7) / 8) * size; // AND mask size
+            totalSize += size * size * 4 + 40 + andMaskSize; // Pixel data + header + AND mask
+        }
+        return totalSize;
+    }
+
+    private static Bitmap drawableToBitmap(Drawable drawable, int width, int height) {
+        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+        Canvas canvas = new Canvas(bitmap);
+        drawable.setBounds(0, 0, width, height);
+        drawable.draw(canvas);
+        return bitmap;
+    }
+
+    private static byte[] bitmapToIcoImageData(Bitmap bitmap) {
+        int width = bitmap.getWidth();
+        int height = bitmap.getHeight();
+
+        int andMaskRowSize = (width + 7) / 8;
+        int andMaskSize = andMaskRowSize * height;
+
+        int bufferSize = width * height * 4 + 40 + andMaskSize;
+
+        ByteBuffer buffer = ByteBuffer.allocate(bufferSize);
+        buffer.order(ByteOrder.LITTLE_ENDIAN);
+
+        // BITMAPINFOHEADER
+        buffer.putInt(40); // Header size
+        buffer.putInt(width); // Width
+        buffer.putInt(height * 2); // Height (times 2 for AND mask)
+        buffer.putShort((short) 1); // Color planes
+        buffer.putShort((short) 32); // Bits per pixel
+        buffer.putInt(0); // Compression
+        buffer.putInt(width * height * 4); // Image size
+        buffer.putInt(0); // Horizontal resolution
+        buffer.putInt(0); // Vertical resolution
+        buffer.putInt(0); // Colors in color table
+        buffer.putInt(0); // Important color count
+
+        // Extract pixel data
+        int[] pixels = new int[width * height];
+        bitmap.getPixels(pixels, 0, width, 0, 0, width, height);
+
+        // Write pixel data (ARGB)
+        for (int y = height - 1; y >= 0; y--) {
+            for (int x = 0; x < width; x++) {
+                int pixel = pixels[y * width + x];
+                buffer.put((byte) (pixel & 0xFF)); // Blue
+                buffer.put((byte) ((pixel >> 8) & 0xFF)); // Green
+                buffer.put((byte) ((pixel >> 16) & 0xFF)); // Red
+                buffer.put((byte) ((pixel >> 24) & 0xFF)); // Alpha
+            }
+        }
+
+        // Write the AND mask (all zeros for no transparency mask)
+        for (int y = 0; y < height; y++) {
+            for (int x = 0; x < andMaskRowSize; x++) {
+                buffer.put((byte) 0); // Write zeroes for the transparency mask
+            }
+        }
+        return buffer.array();
+    }
+}