make screencap able to save pngs.

Change-Id: Idf3542ff05670bc872bd91770810ed775266514f

cmds/screencap/Android.mk

@@ -8,6 +8,7 @@ LOCAL_SHARED_LIBRARIES := \
 	libcutils \
 	libutils \
 	libbinder \
+	libskia \
     libui \
     libsurfaceflinger_client
 
@@ -15,4 +16,11 @@ LOCAL_MODULE:= screencap
 
 LOCAL_MODULE_TAGS := optional
 
+LOCAL_C_INCLUDES += \
+	external/skia/include/core \
+	external/skia/include/effects \
+	external/skia/include/images \
+	external/skia/src/ports \
+	external/skia/include/utils
+
 include $(BUILD_EXECUTABLE)

cmds/screencap/screencap.cpp

@@ -14,29 +14,109 @@
  * limitations under the License.
  */
 
+#include <errno.h>
 #include <unistd.h>
+#include <stdio.h>
 #include <fcntl.h>
 
 #include <binder/IMemory.h>
 #include <surfaceflinger/SurfaceComposerClient.h>
 
+#include <SkImageEncoder.h>
+#include <SkBitmap.h>
+#include <SkStream.h>
+
 using namespace android;
 
+static void usage()
+{
+    fprintf(stderr,
+            "usage: screenshot [-hp] [FILENAME]\n"
+            "   -h: this message\n"
+            "   -p: save the file as a png.\n"
+            "If FILENAME ends with .png it will be saved as a png.\n"
+            "If FILENAME is not given, the results will be printed to stdout.\n"
+    );
+}
+
+static SkBitmap::Config flinger2skia(PixelFormat f)
+{
+    switch (f) {
+        case PIXEL_FORMAT_A_8:
+        case PIXEL_FORMAT_L_8:
+            return SkBitmap::kA8_Config;
+        case PIXEL_FORMAT_RGB_565:
+            return SkBitmap::kRGB_565_Config;
+        case PIXEL_FORMAT_RGBA_4444:
+            return SkBitmap::kARGB_4444_Config;
+        default:
+            return SkBitmap::kARGB_8888_Config;
+    }
+}
+
 int main(int argc, char** argv)
 {
+    bool png = false;
+    int c;
+    while ((c = getopt(argc, argv, "ph")) != -1) {
+        switch (c) {
+            case 'p':
+                png = true;
+                break;
+            case '?':
+            case 'h':
+                usage();
+                return 1;
+        }
+    }
+    argc -= optind;
+    argv += optind;
+
+    int fd = -1;
+    if (argc == 0) {
+        fd = dup(STDOUT_FILENO);
+    } else if (argc == 1) {
+        const char* fn = argv[0];
+        fd = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0664);
+        if (fd == -1) {
+            fprintf(stderr, "Error opening file: (%d) %s\n", errno, strerror(errno));
+            return 1;
+        }
+        const int len = strlen(fn);
+        if (len >= 4 && 0 == strcmp(fn+len-4, ".png")) {
+            png = true;
+        }
+    }
+    
+    if (fd == -1) {
+        usage();
+        return 1;
+    }
+
     ScreenshotClient screenshot;
-    if (screenshot.update() != NO_ERROR)
+    if (screenshot.update() != NO_ERROR) {
         return 0;
+    }
 
     void const* base = screenshot.getPixels();
     uint32_t w = screenshot.getWidth();
     uint32_t h = screenshot.getHeight();
     uint32_t f = screenshot.getFormat();
-    int fd = dup(STDOUT_FILENO);
-    write(fd, &w, 4);
-    write(fd, &h, 4);
-    write(fd, &f, 4);
-    write(fd, base, w*h*4);
+
+    if (png) {
+        SkBitmap b;
+        b.setConfig(flinger2skia(f), w, h);
+        b.setPixels((void*)base);
+        SkDynamicMemoryWStream stream;
+        SkImageEncoder::EncodeStream(&stream, b,
+                SkImageEncoder::kPNG_Type, SkImageEncoder::kDefaultQuality);
+        write(fd, stream.getStream(), stream.getOffset());
+    } else {
+        write(fd, &w, 4);
+        write(fd, &h, 4);
+        write(fd, &f, 4);
+        write(fd, base, w*h*4);
+    }
     close(fd);
     return 0;
 }