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package com.bumptech.glide.request.target;
import android.content.Context;
import android.graphics.Bitmap;
import android.util.Log;
import android.view.Display;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;
import android.view.WindowManager;
import android.widget.ListView;
import com.bumptech.glide.request.Request;
import java.lang.ref.WeakReference;
import java.util.HashSet;
import java.util.Set;
/**
* A base {@link Target} for loading {@link Bitmap}s into {@link View}s that provides default implementations for most
* most methods and can determine the size of views using a
* {@link android.view.ViewTreeObserver.OnDrawListener}.
*
* <p>
* To detect {@link View} reuse in {@link ListView} or any {@link ViewGroup} that reuses views, this class uses the
* {@link View#setTag(Object)} method to store some metadata so that if a view is reused, any previous loads or
* resources from previous loads can be cancelled or reused.
* </p>
*
* <p>
* Any calls to {@link View#setTag(Object)}} on a View given to this class will result in excessive allocations and
* and/or {@link IllegalArgumentException}s. If you must call {@link View#setTag(Object)} on a view, consider
* using {@link BaseTarget} or {@link SimpleTarget} instead.
* </p>
*
* @param <T> The specific subclass of view wrapped by this target.
*/
public abstract class ViewTarget<T extends View, Z> implements Target<Z> {
private static final String TAG = "ViewTarget";
private final T view;
private final SizeDeterminer sizeDeterminer;
public ViewTarget(T view) {
this.view = view;
sizeDeterminer = new SizeDeterminer(view);
}
public T getView() {
return view;
}
@Override
public void getSize(SizeReadyCallback cb) {
sizeDeterminer.getSize(cb);
}
@Override
public void setRequest(Request request) {
view.setTag(request);
}
@Override
public Request getRequest() {
Object tag = view.getTag();
Request request = null;
if (tag != null) {
if (tag instanceof Request) {
request = (Request) tag;
} else {
throw new IllegalArgumentException("You must not call setTag() on a view Glide is targeting");
}
}
return request;
}
@Override
public String toString() {
return "Target for: " + view;
}
private static class SizeDeterminer {
private final View view;
private Set<SizeReadyCallback> cbs = new HashSet<SizeReadyCallback>();
private SizeDeterminerLayoutListener layoutListener;
public SizeDeterminer(View view) {
this.view = view;
}
private void notifyCbs(int width, int height) {
for (SizeReadyCallback cb : cbs) {
cb.onSizeReady(width, height);
}
cbs.clear();
}
private void checkCurrentDimens() {
if (cbs.isEmpty()) {
return;
}
boolean calledCallback = true;
ViewGroup.LayoutParams layoutParams = view.getLayoutParams();
if (isViewSizeValid()) {
notifyCbs(view.getWidth(), view.getHeight());
} else if (isLayoutParamsSizeValid()) {
notifyCbs(layoutParams.width, layoutParams.height);
} else {
calledCallback = false;
}
if (calledCallback) {
// Keep a reference to the layout listener and remove it here
// rather than having the observer remove itself because the observer
// we add the listener to will be almost immediately merged into
// another observer and will therefore never be alive. If we instead
// keep a reference to the listener and remove it here, we get the
// current view tree observer and should succeed.
ViewTreeObserver observer = view.getViewTreeObserver();
if (observer.isAlive()) {
observer.removeOnPreDrawListener(layoutListener);
}
}
}
public void getSize(SizeReadyCallback cb) {
ViewGroup.LayoutParams layoutParams = view.getLayoutParams();
if (isViewSizeValid()) {
cb.onSizeReady(view.getWidth(), view.getHeight());
} else if (isLayoutParamsSizeValid()) {
cb.onSizeReady(layoutParams.width, layoutParams.height);
} else if (isUsingWrapContent()) {
WindowManager windowManager =
(WindowManager) view.getContext().getSystemService(Context.WINDOW_SERVICE);
Display display = windowManager.getDefaultDisplay();
final int width = display.getWidth();
final int height = display.getHeight();
if (Log.isLoggable(TAG, Log.WARN)) {
Log.w(TAG, "Trying to load image into ImageView using WRAP_CONTENT, defaulting to screen" +
" dimensions: [" + width + "x" + height + "]. Give the view an actual width and height " +
" for better performance.");
}
cb.onSizeReady(display.getWidth(), display.getHeight());
} else {
cbs.add(cb);
final ViewTreeObserver observer = view.getViewTreeObserver();
layoutListener = new SizeDeterminerLayoutListener(this);
observer.addOnPreDrawListener(layoutListener);
}
}
private boolean isViewSizeValid() {
return view.getWidth() > 0 && view.getHeight() > 0;
}
private boolean isUsingWrapContent() {
final ViewGroup.LayoutParams layoutParams = view.getLayoutParams();
return layoutParams != null && (layoutParams.width == ViewGroup.LayoutParams.WRAP_CONTENT
|| layoutParams.height == ViewGroup.LayoutParams.WRAP_CONTENT);
}
private boolean isLayoutParamsSizeValid() {
final ViewGroup.LayoutParams layoutParams = view.getLayoutParams();
return layoutParams != null && (layoutParams.width > 0 && layoutParams.height > 0);
}
private static class SizeDeterminerLayoutListener implements ViewTreeObserver.OnPreDrawListener {
private final WeakReference<SizeDeterminer> sizeDeterminerRef;
public SizeDeterminerLayoutListener(SizeDeterminer sizeDeterminer) {
sizeDeterminerRef = new WeakReference<SizeDeterminer>(sizeDeterminer);
}
@Override
public boolean onPreDraw() {
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Log.v(TAG, "OnGlobalLayoutListener called listener=" + this);
}
SizeDeterminer sizeDeterminer = sizeDeterminerRef.get();
if (sizeDeterminer != null) {
sizeDeterminer.checkCurrentDimens();
}
return true;
}
}
}
}
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