Pebble: Support taking Pebble Time screenshots. Closes #97.

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/pebble/PebbleProtocol.java

@@ -202,6 +202,97 @@ public class PebbleProtocol extends GBDeviceProtocol {
     GBDeviceEventScreenshot mDevEventScreenshot = null;
     int mScreenshotRemaining = -1;
 
+    //monochrome black + white
+    static final byte[] clut_pebble = {
+            0x00, 0x00, 0x00, 0x00,
+            (byte) 0xff, (byte) 0xff, (byte) 0xff, 0x00
+    };
+
+    // linear BGR222 (6 bit, 64 entries)
+    static final byte[] clut_pebbletime = new byte[]{
+            0x00, 0x00, 0x00, 0x00,
+            0x55, 0x00, 0x00, 0x00,
+            (byte) 0xaa, 0x00, 0x00, 0x00,
+            (byte) 0xff, 0x00, 0x00, 0x00,
+
+            0x00, 0x55, 0x00, 0x00,
+            0x55, 0x55, 0x00, 0x00,
+            (byte) 0xaa, 0x55, 0x00, 0x00,
+            (byte) 0xff, 0x55, 0x00, 0x00,
+
+            0x00, (byte) 0xaa, 0x00, 0x00,
+            0x55, (byte) 0xaa, 0x00, 0x00,
+            (byte) 0xaa, (byte) 0xaa, 0x00, 0x00,
+            (byte) 0xff, (byte) 0xaa, 0x00, 0x00,
+
+            0x00, (byte) 0xff, 0x00, 0x00,
+            0x55, (byte) 0xff, 0x00, 0x00,
+            (byte) 0xaa, (byte) 0xff, 0x00, 0x00,
+            (byte) 0xff, (byte) 0xff, 0x00, 0x00,
+
+            0x00, 0x00, 0x55, 0x00,
+            0x55, 0x00, 0x55, 0x00,
+            (byte) 0xaa, 0x00, 0x55, 0x00,
+            (byte) 0xff, 0x00, 0x55, 0x00,
+
+            0x00, 0x55, 0x55, 0x00,
+            0x55, 0x55, 0x55, 0x00,
+            (byte) 0xaa, 0x55, 0x55, 0x00,
+            (byte) 0xff, 0x55, 0x55, 0x00,
+
+            0x00, (byte) 0xaa, 0x55, 0x00,
+            0x55, (byte) 0xaa, 0x55, 0x00,
+            (byte) 0xaa, (byte) 0xaa, 0x55, 0x00,
+            (byte) 0xff, (byte) 0xaa, 0x55, 0x00,
+
+            0x00, (byte) 0xff, 0x55, 0x00,
+            0x55, (byte) 0xff, 0x55, 0x00,
+            (byte) 0xaa, (byte) 0xff, 0x55, 0x00,
+            (byte) 0xff, (byte) 0xff, 0x55, 0x00,
+
+            0x00, 0x00, (byte) 0xaa, 0x00,
+            0x55, 0x00, (byte) 0xaa, 0x00,
+            (byte) 0xaa, 0x00, (byte) 0xaa, 0x00,
+            (byte) 0xff, 0x00, (byte) 0xaa, 0x00,
+
+            0x00, 0x55, (byte) 0xaa, 0x00,
+            0x55, 0x55, (byte) 0xaa, 0x00,
+            (byte) 0xaa, 0x55, (byte) 0xaa, 0x00,
+            (byte) 0xff, 0x55, (byte) 0xaa, 0x00,
+
+            0x00, (byte) 0xaa, (byte) 0xaa, 0x00,
+            0x55, (byte) 0xaa, (byte) 0xaa, 0x00,
+            (byte) 0xaa, (byte) 0xaa, (byte) 0xaa, 0x00,
+            (byte) 0xff, (byte) 0xaa, (byte) 0xaa, 0x00,
+
+            0x00, (byte) 0xff, (byte) 0xaa, 0x00,
+            0x55, (byte) 0xff, (byte) 0xaa, 0x00,
+            (byte) 0xaa, (byte) 0xff, (byte) 0xaa, 0x00,
+            (byte) 0xff, (byte) 0xff, (byte) 0xaa, 0x00,
+
+            0x00, 0x00, (byte) 0xff, 0x00,
+            0x55, 0x00, (byte) 0xff, 0x00,
+            (byte) 0xaa, 0x00, (byte) 0xff, 0x00,
+            (byte) 0xff, 0x00, (byte) 0xff, 0x00,
+
+            0x00, 0x55, (byte) 0xff, 0x00,
+            0x55, 0x55, (byte) 0xff, 0x00,
+            (byte) 0xaa, 0x55, (byte) 0xff, 0x00,
+            (byte) 0xff, 0x55, (byte) 0xff, 0x00,
+
+            0x00, (byte) 0xaa, (byte) 0xff, 0x00,
+            0x55, (byte) 0xaa, (byte) 0xff, 0x00,
+            (byte) 0xaa, (byte) 0xaa, (byte) 0xff, 0x00,
+            (byte) 0xff, (byte) 0xaa, (byte) 0xff, 0x00,
+
+            0x00, (byte) 0xff, (byte) 0xff, 0x00,
+            0x55, (byte) 0xff, (byte) 0xff, 0x00,
+            (byte) 0xaa, (byte) 0xff, (byte) 0xff, 0x00,
+            (byte) 0xff, (byte) 0xff, (byte) 0xff, 0x00,
+
+    };
+
+
     byte last_id = -1;
     private ArrayList<UUID> tmpUUIDS = new ArrayList<>();
 
@@ -477,7 +568,7 @@ public class PebbleProtocol extends GBDeviceProtocol {
         buf.putInt(timestamp); // 32-bit timestamp
         buf.putShort((short) 0); // duration
         buf.put((byte) 0x01); // type (0x01 = notification)
-        buf.putShort((short) 0x0001); // flags 0x0001 = ?
+        buf.putShort((short) 0x001f); // flags 0x0001 = ?
         buf.put((byte) 0x04); // layout (0x04 = notification?)
         buf.putShort(attributes_length); // total length of all attributes and actions in bytes
         buf.put(attributes_count);
@@ -506,7 +597,7 @@ public class PebbleProtocol extends GBDeviceProtocol {
 
         if (mForceProtocol) {
             // ACTION
-            buf.put((byte) 0x01); // id
+            buf.put((byte) 0x00); // id
             buf.put((byte) 0x04); // dismiss action
             buf.put((byte) 0x01); // number attributes
             buf.put((byte) 0x01); // attribute id (title)
@@ -921,34 +1012,38 @@ public class PebbleProtocol extends GBDeviceProtocol {
             byte result = buf.get();
             mDevEventScreenshot = new GBDeviceEventScreenshot();
             int version = buf.getInt();
-            if (result != 0 || version != 1) { // pebble time not yet
+            if (result != 0) {
                 return null;
             }
             mDevEventScreenshot.width = buf.getInt();
             mDevEventScreenshot.height = buf.getInt();
-            mDevEventScreenshot.bpp = 1;
-            mDevEventScreenshot.clut = new byte[]{
-                    0x00, 0x00, 0x00, 0x00, (byte) 0xff,
-                    (byte) 0xff, (byte) 0xff, 0x00
-            };
 
-            mScreenshotRemaining = (mDevEventScreenshot.width * mDevEventScreenshot.height) / 8;
+            if (version == 1) {
-            if (mScreenshotRemaining > 50000) {
+                mDevEventScreenshot.bpp = 1;
-                mScreenshotRemaining = -1; // ignore too big values
+                mDevEventScreenshot.clut = clut_pebble;
-                return null;
+            } else {
+                mDevEventScreenshot.bpp = 8;
+                mDevEventScreenshot.clut = clut_pebbletime;
             }
+
+            mScreenshotRemaining = (mDevEventScreenshot.width * mDevEventScreenshot.height * mDevEventScreenshot.bpp) / 8;
+
             mDevEventScreenshot.data = new byte[mScreenshotRemaining];
             length -= 13;
         }
         if (mScreenshotRemaining == -1) {
             return null;
         }
-
         for (int i = 0; i < length; i++) {
-            byte corrected = reverseBits(buf.get());
+            byte corrected = buf.get();
+            if (mDevEventScreenshot.bpp == 1) {
+                corrected = reverseBits(corrected);
+            } else {
+                corrected = (byte) (corrected & 0b00111111);
+            }
+
             mDevEventScreenshot.data[mDevEventScreenshot.data.length - mScreenshotRemaining + i] = corrected;
         }
-
         mScreenshotRemaining -= length;
         LOG.info("Screenshot remaining bytes " + mScreenshotRemaining);
         if (mScreenshotRemaining == 0) {

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/util/GB.java

@@ -151,16 +151,16 @@ public class GB {
             headerbuf.putInt(screenshot.width);
             headerbuf.putInt(-screenshot.height);
             headerbuf.putShort((short) 1); // planes
-            headerbuf.putShort((short) 1); // bit count
+            headerbuf.putShort((short) screenshot.bpp);
             headerbuf.putInt(0); // compression
             headerbuf.putInt(0); // length of pixeldata in byte (uncompressed=0)
             headerbuf.putInt(0); // pixels per meter (x)
             headerbuf.putInt(0); // pixels per meter (y)
-            headerbuf.putInt(2); // number of colors in CLUT
+            headerbuf.putInt(screenshot.clut.length / 4); // number of colors in CLUT
-            headerbuf.putInt(2); // numbers of used colors
+            headerbuf.putInt(0); // numbers of used colors
             headerbuf.put(screenshot.clut);
             fos.write(headerbuf.array());
-            int rowbytes = screenshot.width / 8;
+            int rowbytes = (screenshot.width * screenshot.bpp) / 8;
             byte[] pad = new byte[rowbytes % 4];
             for (int i = 0; i < screenshot.height; i++) {
                 fos.write(screenshot.data, rowbytes * i, rowbytes);