/*******************************************************************************
* This file is part of RedReader.
*
* RedReader is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* RedReader is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with RedReader. If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/
package org.quantumbadger.redreader.views;
public abstract class RRAnimation implements RRChoreographer.Callback {
private static final RRChoreographer CHOREOGRAPHER = RRChoreographer.getInstance();
private long mFirstFrameNanos = -1;
private boolean mStarted = false;
private boolean mStopped = false;
public final void start() {
if(mStarted) {
throw new RuntimeException("Attempted to start animation twice!");
}
mStarted = true;
CHOREOGRAPHER.postFrameCallback(this);
}
public final void stop() {
if(!mStarted) {
throw new RuntimeException("Attempted to stop animation before it's started!");
}
if(mStopped) {
throw new RuntimeException("Attempted to stop animation twice!");
}
mStopped = true;
}
// Return true to continue animating
protected abstract boolean handleFrame(final long nanosSinceAnimationStart);
@Override
public final void doFrame(final long frameTimeNanos) {
if(mStopped) {
return;
}
if(mFirstFrameNanos == -1) {
mFirstFrameNanos = frameTimeNanos;
}
if(handleFrame(frameTimeNanos - mFirstFrameNanos)) {
CHOREOGRAPHER.postFrameCallback(this);
}
}
}