I need help with NinePatchDrawable:
My app can download themes from the network. Almost all things work fine, except 9-Patch PNGs.
final Bitmap bubble = getFromTheme("bubble");
if (bubble == null) return null;
final byte[] chunk = bubble.getNinePatchChunk();
if (!NinePatch.isNinePatchChunk(chunk)) return null;
NinePatchDrawable d = new NinePatchDrawable(getResources(), bubble, chunk, new Rect(), null);
v.setBackgroundDrawable(d);
d = null;
System.gc();
getFromTheme() loads the Bitmap from the SD card. The 9-Patch PNGs are already compiled, that means they include the required chunk.
The way how I convert the Bitmap to a NinePatchDrawable object seems to be working, because the image is stretchable as well as I drew it.
The only thing that doesn't work is the padding. I already tried to set the padding to the view like this:
final Rect rect = new Rect(); // or just use the new Rect() set
d.getPadding(rect); // in the constructor
v.setPadding(rect.left, rect.top, rect.right, rect.bottom);
d.getPadding(rect) should fill the variable rect with the padding got from the chunk, shouldn't it? But it doesn't.
Result: The TextView (v) does not show the text in the content area of the 9-Patch image. The paddings are set to 0 in each coordinate.
Thanks for reading.
Finally, I did it. Android wasn't interpreting the chunk data correctly. There might be bug. So you have to deserialize the chunk yourself to get the padding data.
Here we go:
package com.dragonwork.example;
import android.graphics.Rect;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
class NinePatchChunk {
public static final int NO_COLOR = 0x00000001;
public static final int TRANSPARENT_COLOR = 0x00000000;
public final Rect mPaddings = new Rect();
public int mDivX[];
public int mDivY[];
public int mColor[];
private static void readIntArray(final int[] data, final ByteBuffer buffer) {
for (int i = 0, n = data.length; i < n; ++i)
data[i] = buffer.getInt();
}
private static void checkDivCount(final int length) {
if (length == 0 || (length & 0x01) != 0)
throw new RuntimeException("invalid nine-patch: " + length);
}
public static NinePatchChunk deserialize(final byte[] data) {
final ByteBuffer byteBuffer =
ByteBuffer.wrap(data).order(ByteOrder.nativeOrder());
if (byteBuffer.get() == 0) return null; // is not serialized
final NinePatchChunk chunk = new NinePatchChunk();
chunk.mDivX = new int[byteBuffer.get()];
chunk.mDivY = new int[byteBuffer.get()];
chunk.mColor = new int[byteBuffer.get()];
checkDivCount(chunk.mDivX.length);
checkDivCount(chunk.mDivY.length);
// skip 8 bytes
byteBuffer.getInt();
byteBuffer.getInt();
chunk.mPaddings.left = byteBuffer.getInt();
chunk.mPaddings.right = byteBuffer.getInt();
chunk.mPaddings.top = byteBuffer.getInt();
chunk.mPaddings.bottom = byteBuffer.getInt();
// skip 4 bytes
byteBuffer.getInt();
readIntArray(chunk.mDivX, byteBuffer);
readIntArray(chunk.mDivY, byteBuffer);
readIntArray(chunk.mColor, byteBuffer);
return chunk;
}
}
Use the class above as following:
final byte[] chunk = bitmap.getNinePatchChunk();
if (NinePatch.isNinePatchChunk(chunk)) {
textView.setBackgroundDrawable(new NinePatchDrawable(getResources(),
bitmap, chunk, NinePatchChunk.deserialize(chunk).mPaddings, null));
}
And it will work perfectly!