/**
* Acquire the lock so that the scene can be acted upon.
*
* <p>This returns null if the lock was just acquired, otherwise it returns {@link
* Result.Status#SUCCESS} if the lock already belonged to that thread, or another instance (see
* {@link Result#getStatus()}) if an error occurred.
*
* @param timeout the time to wait if another rendering is happening.
* @return null if the lock was just acquire or another result depending on the state.
* @throws IllegalStateException if the current context is different than the one owned by the
* scene.
*/
private Result acquireLock(long timeout) {
ReentrantLock lock = Bridge.getLock();
if (!lock.isHeldByCurrentThread()) {
try {
boolean acquired = lock.tryLock(timeout, TimeUnit.MILLISECONDS);
if (!acquired) {
return ERROR_TIMEOUT.createResult();
}
} catch (InterruptedException e) {
return ERROR_LOCK_INTERRUPTED.createResult();
}
} else {
// This thread holds the lock already. Checks that this wasn't for a different context.
// If this is called by init, mContext will be null and so should sCurrentContext
// anyway
if (mContext != sCurrentContext) {
throw new IllegalStateException(
"Acquiring different scenes from same thread without releases");
}
return SUCCESS.createResult();
}
return null;
}
/**
* Prepares the scene for action.
*
* <p>This call is blocking if another rendering/inflating is currently happening, and will return
* whether the preparation worked.
*
* <p>The preparation can fail if another rendering took too long and the timeout was elapsed.
*
* <p>More than one call to this from the same thread will have no effect and will return {@link
* Result.Status#SUCCESS}.
*
* <p>After scene actions have taken place, only one call to {@link #release()} must be done.
*
* @param timeout the time to wait if another rendering is happening.
* @return whether the scene was prepared
* @see #release()
* @throws IllegalStateException if {@link #init(long)} was never called.
*/
public Result acquire(long timeout) {
if (mContext == null) {
throw new IllegalStateException("After scene creation, #init() must be called");
}
// acquire the lock. if the result is null, lock was just acquired, otherwise, return
// the result.
Result result = acquireLock(timeout);
if (result != null) {
return result;
}
setUp();
return SUCCESS.createResult();
}
/**
* Initializes and acquires the scene, creating various Android objects such as context, inflater,
* and parser.
*
* @param timeout the time to wait if another rendering is happening.
* @return whether the scene was prepared
* @see #acquire(long)
* @see #release()
*/
public Result init(long timeout) {
// acquire the lock. if the result is null, lock was just acquired, otherwise, return
// the result.
Result result = acquireLock(timeout);
if (result != null) {
return result;
}
// setup the ParserFactory
ParserFactory.setParserFactory(mParams.getLayoutlibCallback().getParserFactory());
HardwareConfig hardwareConfig = mParams.getHardwareConfig();
// setup the display Metrics.
DisplayMetrics metrics = new DisplayMetrics();
metrics.densityDpi = metrics.noncompatDensityDpi = hardwareConfig.getDensity().getDpiValue();
metrics.density =
metrics.noncompatDensity = metrics.densityDpi / (float) DisplayMetrics.DENSITY_DEFAULT;
metrics.scaledDensity = metrics.noncompatScaledDensity = metrics.density;
metrics.widthPixels = metrics.noncompatWidthPixels = hardwareConfig.getScreenWidth();
metrics.heightPixels = metrics.noncompatHeightPixels = hardwareConfig.getScreenHeight();
metrics.xdpi = metrics.noncompatXdpi = hardwareConfig.getXdpi();
metrics.ydpi = metrics.noncompatYdpi = hardwareConfig.getYdpi();
RenderResources resources = mParams.getResources();
// build the context
mContext =
new BridgeContext(
mParams.getProjectKey(),
metrics,
resources,
mParams.getAssets(),
mParams.getLayoutlibCallback(),
getConfiguration(),
mParams.getTargetSdkVersion(),
mParams.isRtlSupported());
setUp();
return SUCCESS.createResult();
}