Android Wear Picture ticker

Question

I am using the sample second, hour, and minute ticker/clock hands for a sample watch face on Android Studio. There, draw line method of Canvas class is being used with a startX, startY, stopX, and stopY. My question is how do I implement this similarly using a picture? I thought of using drawBitmap which only has a left and top and so it rotates but way too widely and not in place as the hands do. Is there any way to use an image instead of a line like in the drawLine method? The bottom line is that I need to use an image instead of a line as a clock hand.

Thanks!

See: http://stackoverflow.com/questions/4166917/android-how-to-rotate-a-bitmap-on-a-center-point — Morrison Chang, Jan 09 '15 at 23:53

score 2 · Accepted Answer · answered Jan 10 '15 at 01:06

You should use Canvas.save, Canvas.rotate and Canvas.restore. Imagine, that you always draw things in the same place, but the underlying canvas is being rotated, so you will draw in the right place. Consider the example from the Santa Tracker:

for (int i = 0; i < mCloudBitmaps.length; i++) {
    canvas.save();
    canvas.rotate(mCloudDegrees[i], centerX, centerY);
    float r = centerX - (timeElapsed / (mCloudSpeeds[i])) % centerX;
    mCloudFilterPaints[i].setAlpha((int) (r / centerX * 255));
    canvas.drawBitmap(mCloudBitmaps[i], centerX, centerY - r,
        mCloudFilterPaints[i]);
    canvas.restore(); 
}

It doesn't draw hands, but instead the clouds on the watch face, but it should give you an example of what you need to try to do.

Android Wear Picture ticker

1 Answers1