4 files changed, 56 insertions, 82 deletions

diff --git a/java/org/gnu/emacs/EmacsDrawRectangle.java b/java/org/gnu/emacs/EmacsDrawRectangle.java
index e40a7c16068..ea0f1c28106 100644
--- a/java/org/gnu/emacs/EmacsDrawRectangle.java
+++ b/java/org/gnu/emacs/EmacsDrawRectangle.java
@@ -22,13 +22,23 @@ package org.gnu.emacs;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
 import android.graphics.Paint;
+import android.graphics.PorterDuff.Mode;
+import android.graphics.PorterDuffXfermode;
 import android.graphics.Rect;
 import android.graphics.RectF;
+import android.graphics.Xfermode;
 
 import android.util.Log;
 
 public final class EmacsDrawRectangle
 {
+  private static final Xfermode srcInAlu;
+
+  static
+  {
+    srcInAlu = new PorterDuffXfermode (Mode.SRC_IN);
+  };
+
   public static void
   perform (EmacsDrawable drawable, EmacsGC gc,
            int x, int y, int width, int height)
@@ -40,8 +50,10 @@ public final class EmacsDrawRectangle
     Canvas canvas;
     Bitmap clipBitmap;
 
-    /* TODO implement stippling.  */
-    if (gc.fill_style == EmacsGC.GC_FILL_OPAQUE_STIPPLED)
+    /* TODO implement stippling for this request.  */
+    if (gc.fill_style == EmacsGC.GC_FILL_OPAQUE_STIPPLED
+        /* And GC_INVERT also.  */
+        || gc.fill_style == EmacsGC.GC_INVERT)
       return;
 
     canvas = drawable.lockCanvas (gc);
@@ -103,7 +115,7 @@ public final class EmacsDrawRectangle
         /* Set the transfer mode to SRC_IN to preserve only the parts
            of the source that overlap with the mask.  */
         maskPaint = new Paint ();
-        maskPaint.setXfermode (EmacsGC.srcInAlu);
+        maskPaint.setXfermode (srcInAlu);
         maskPaint.setStyle (Paint.Style.STROKE);
 
         /* Draw the source.  */
diff --git a/java/org/gnu/emacs/EmacsFillRectangle.java b/java/org/gnu/emacs/EmacsFillRectangle.java
index f338a54f97b..7642deed7c3 100644
--- a/java/org/gnu/emacs/EmacsFillRectangle.java
+++ b/java/org/gnu/emacs/EmacsFillRectangle.java
@@ -21,6 +21,8 @@ package org.gnu.emacs;
 
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
+import android.graphics.ColorFilter;
+import android.graphics.ColorMatrixColorFilter;
 import android.graphics.Paint;
 import android.graphics.Rect;
 
@@ -28,30 +30,42 @@ import android.util.Log;
 
 public final class EmacsFillRectangle
 {
+  /* Color filter that inverts colors from the source.  */
+  private static final ColorFilter invertFilter;
+
+  static
+  {
+    invertFilter = new ColorMatrixColorFilter (new float[] {
+        -1f, 0f, 0f, 0f, 255f,
+        0f, -1f, 0f, 0f, 255f,
+        0f, 0f, -1f, 0f, 255f,
+        0f, 0f, 0f, 1f, 0f,
+      });
+  };
+
   public static void
   perform (EmacsDrawable drawable, EmacsGC gc,
            int x, int y, int width, int height)
   {
-    Paint maskPaint, paint;
-    Canvas maskCanvas;
-    Bitmap maskBitmap;
+    Paint paint;
     Rect rect;
-    Rect maskRect, dstRect;
     Canvas canvas;
-    Bitmap clipBitmap;
+    Bitmap invertBitmap;
 
     canvas = drawable.lockCanvas (gc);
 
-    if (canvas == null)
+    /* Clip masks are not respected or implemented when specified with
+       this request.  */
+    if (canvas == null || gc.clip_mask != null)
       return;
 
     rect = new Rect (x, y, x + width, y + height);
 
-    paint = gc.gcPaint;
-    paint.setStyle (Paint.Style.FILL);
-
-    if (gc.clip_mask == null)
+    if (gc.function != EmacsGC.GC_INVERT)
       {
+        paint = gc.gcPaint;
+        paint.setStyle (Paint.Style.FILL);
+
         if (gc.fill_style != EmacsGC.GC_FILL_OPAQUE_STIPPLED)
           canvas.drawRect (rect, paint);
         else
@@ -59,57 +73,17 @@ public final class EmacsFillRectangle
       }
     else
       {
-        /* Drawing with a clip mask involves calculating the
-           intersection of the clip mask with the dst rect, and
-           extrapolating the corresponding part of the src rect.  */
-
-        clipBitmap = gc.clip_mask.bitmap;
-        dstRect = new Rect (x, y, x + width, y + height);
-        maskRect = new Rect (gc.clip_x_origin,
-                             gc.clip_y_origin,
-                             (gc.clip_x_origin
-                              + clipBitmap.getWidth ()),
-                             (gc.clip_y_origin
-                              + clipBitmap.getHeight ()));
-
-        if (!maskRect.setIntersect (dstRect, maskRect))
-          /* There is no intersection between the clip mask and the
-             dest rect.  */
-          return;
-
-        /* Finally, create a temporary bitmap that is the size of
-           maskRect.  */
-
-        maskBitmap
-          = Bitmap.createBitmap (maskRect.width (), maskRect.height (),
-                                 Bitmap.Config.ARGB_8888);
-
-        /* Draw the mask onto the maskBitmap.  */
-        maskCanvas = new Canvas (maskBitmap);
-        maskRect.offset (-gc.clip_x_origin,
-                         -gc.clip_y_origin);
-        maskCanvas.drawBitmap (gc.clip_mask.bitmap,
-                               maskRect, new Rect (0, 0,
-                                                   maskRect.width (),
-                                                   maskRect.height ()),
-                               paint);
-        maskRect.offset (gc.clip_x_origin,
-                         gc.clip_y_origin);
-
-        /* Set the transfer mode to SRC_IN to preserve only the parts
-           of the source that overlap with the mask.  */
-        maskPaint = new Paint ();
-        maskPaint.setXfermode (EmacsGC.srcInAlu);
-
-        /* Draw the source.  */
-        maskCanvas.drawRect (maskRect, maskPaint);
-
-        /* Finally, draw the mask bitmap to the destination.  */
-        paint.setXfermode (null);
-        canvas.drawBitmap (maskBitmap, null, maskRect, paint);
-
-        /* Recycle this unused bitmap.  */
-        maskBitmap.recycle ();
+        paint = new Paint ();
+
+        /* Simply invert the destination, which is only implemented for
+           this request.  As Android doesn't permit copying a bitmap to
+           itself, a copy of the source must be procured beforehand.  */
+        invertBitmap = Bitmap.createBitmap (drawable.getBitmap (),
+                                            x, y, width, height);
+        paint.setColorFilter (invertFilter);
+        canvas.drawBitmap (invertBitmap, null, rect, paint);
+        paint.setColorFilter (null);
+        invertBitmap.recycle ();
       }
 
     drawable.damageRect (rect);
diff --git a/java/org/gnu/emacs/EmacsGC.java b/java/org/gnu/emacs/EmacsGC.java
index ec2b9c9e475..bb11f76c800 100644
--- a/java/org/gnu/emacs/EmacsGC.java
+++ b/java/org/gnu/emacs/EmacsGC.java
@@ -27,9 +27,7 @@ import android.graphics.Canvas;
 import android.graphics.ColorFilter;
 import android.graphics.PorterDuff.Mode;
 import android.graphics.PorterDuffColorFilter;
-import android.graphics.PorterDuffXfermode;
 import android.graphics.Shader.TileMode;
-import android.graphics.Xfermode;
 
 import android.graphics.drawable.BitmapDrawable;
 
@@ -40,8 +38,8 @@ import android.os.Build;
 
 public final class EmacsGC extends EmacsHandleObject
 {
-  public static final int GC_COPY = 0;
-  public static final int GC_XOR  = 1;
+  public static final int GC_COPY    = 0;
+  public static final int GC_INVERT  = 1;
 
   public static final int GC_FILL_SOLID                 = 0;
   public static final int GC_FILL_OPAQUE_STIPPLED       = 1;
@@ -49,8 +47,6 @@ public final class EmacsGC extends EmacsHandleObject
   public static final int GC_LINE_SOLID                 = 0;
   public static final int GC_LINE_ON_OFF_DASH           = 1;
 
-  public static final Xfermode xorAlu, srcInAlu;
-
   public int function, fill_style;
   public int foreground, background;
   public int clip_x_origin, clip_y_origin;
@@ -72,12 +68,6 @@ public final class EmacsGC extends EmacsHandleObject
      rectangles changed.  0 if there are no clip rectangles.  */
   public long clipRectID;
 
-  static
-  {
-    xorAlu = new PorterDuffXfermode (Mode.XOR);
-    srcInAlu = new PorterDuffXfermode (Mode.SRC_IN);
-  }
-
   /* The following fields are only set on immutable GCs.  */
 
   public
@@ -131,8 +121,6 @@ public final class EmacsGC extends EmacsHandleObject
     /* A line_width of 0 is equivalent to that of 1.  */
     gcPaint.setStrokeWidth (line_width < 1 ? 1 : line_width);
     gcPaint.setColor (foreground | 0xff000000);
-    gcPaint.setXfermode (function == GC_XOR
-                         ? xorAlu : srcInAlu);
 
     /* Update the stipple object with the new stipple bitmap, or delete
        it if the stipple has been cleared on systems too old to support
diff --git a/java/org/gnu/emacs/EmacsSafThread.java b/java/org/gnu/emacs/EmacsSafThread.java
index 14c3f222833..ee8c2e7e0c3 100644
--- a/java/org/gnu/emacs/EmacsSafThread.java
+++ b/java/org/gnu/emacs/EmacsSafThread.java
@@ -1623,10 +1623,10 @@ public final class EmacsSafThread extends HandlerThread
        mode is merely w.
 
        This may be ascribed to a mix-up in Android's documentation
-       regardin DocumentsProvider: the `openDocument' function is only
-       documented to accept r or rw, whereas the default
-       implementation of the `openFile' function (which documents rwt)
-       delegates to `openDocument'.  */
+       regarding DocumentsProvider: the `openDocument' function is only
+       documented to accept r or rw, whereas the default implementation
+       of the `openFile' function (which documents rwt) delegates to
+       `openDocument'.  */
 
     if (read && write && truncate && fileDescriptor != null
         && !EmacsNative.ftruncate (fileDescriptor.getFd ()))