/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.support.transition;
import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ObjectAnimator;
import android.annotation.TargetApi;
import android.support.annotation.RequiresApi;
import android.support.v4.view.ViewCompat;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
/**
* This transition tracks changes to the visibility of target views in the
* start and end scenes and fades views in or out when they become visible
* or non-visible. Visibility is determined by both the
* {@link View#setVisibility(int)} state of the view as well as whether it
* is parented in the current view hierarchy.
*
* <p>The ability of this transition to fade out a particular view, and the
* way that that fading operation takes place, is based on
* the situation of the view in the view hierarchy. For example, if a view was
* simply removed from its parent, then the view will be added into a {@link
* android.view.ViewGroupOverlay} while fading. If a visible view is
* changed to be {@link View#GONE} or {@link View#INVISIBLE}, then the
* visibility will be changed to {@link View#VISIBLE} for the duration of
* the animation. However, if a view is in a hierarchy which is also altering
* its visibility, the situation can be more complicated. In general, if a
* view that is no longer in the hierarchy in the end scene still has a
* parent (so its parent hierarchy was removed, but it was not removed from
* its parent), then it will be left alone to avoid side-effects from
* improperly removing it from its parent. The only exception to this is if
* the previous {@link android.transition.Scene} was
* {@link ScenePort#getSceneForLayout(ViewGroup, int, android.content.Context)
* created from a layout resource file}, then it is considered safe to un-parent
* the starting scene view in order to fade it out.</p>
*
* <p>A Fade transition can be described in a resource file by using the
* tag <code>fade</code>, along with the standard
* attributes of {@link android.R.styleable#Fade} and
* {@link android.R.styleable#Transition}.</p>
*/
@RequiresApi(14)
@TargetApi(14)
class FadePort extends VisibilityPort {
/**
* Fading mode used in {@link #FadePort(int)} to make the transition
* operate on targets that are appearing. Maybe be combined with
* {@link #OUT} to fade both in and out.
*/
public static final int IN = 0x1;
/**
* Fading mode used in {@link #FadePort(int)} to make the transition
* operate on targets that are disappearing. Maybe be combined with
* {@link #IN} to fade both in and out.
*/
public static final int OUT = 0x2;
private static final String LOG_TAG = "Fade";
private static final String PROPNAME_SCREEN_X = "android:fade:screenX";
private static final String PROPNAME_SCREEN_Y = "android:fade:screenY";
private static boolean DBG = TransitionPort.DBG && false;
private int mFadingMode;
/**
* Constructs a Fade transition that will fade targets in and out.
*/
public FadePort() {
this(IN | OUT);
}
/**
* Constructs a Fade transition that will fade targets in
* and/or out, according to the value of fadingMode.
*
* @param fadingMode The behavior of this transition, a combination of
* {@link #IN} and {@link #OUT}.
*/
public FadePort(int fadingMode) {
mFadingMode = fadingMode;
}
/**
* Utility method to handle creating and running the Animator.
*/
private Animator createAnimation(View view, float startAlpha, float endAlpha,
AnimatorListenerAdapter listener) {
if (startAlpha == endAlpha) {
// run listener if we're noop'ing the animation, to get the end-state results now
if (listener != null) {
listener.onAnimationEnd(null);
}
return null;
}
final ObjectAnimator anim = ObjectAnimator.ofFloat(view, "alpha", startAlpha,
endAlpha);
if (DBG) {
Log.d(LOG_TAG, "Created animator " + anim);
}
if (listener != null) {
anim.addListener(listener);
}
return anim;
}
private void captureValues(TransitionValues transitionValues) {
int[] loc = new int[2];
transitionValues.view.getLocationOnScreen(loc);
transitionValues.values.put(PROPNAME_SCREEN_X, loc[0]);
transitionValues.values.put(PROPNAME_SCREEN_Y, loc[1]);
}
@Override
public void captureStartValues(TransitionValues transitionValues) {
super.captureStartValues(transitionValues);
captureValues(transitionValues);
}
@Override
public Animator onAppear(ViewGroup sceneRoot,
TransitionValues startValues, int startVisibility,
TransitionValues endValues, int endVisibility) {
if ((mFadingMode & IN) != IN || endValues == null) {
return null;
}
final View endView = endValues.view;
if (DBG) {
View startView = (startValues != null) ? startValues.view : null;
Log.d(LOG_TAG, "Fade.onAppear: startView, startVis, endView, endVis = " +
startView + ", " + startVisibility + ", " + endView + ", " + endVisibility);
}
endView.setAlpha(0);
TransitionListener transitionListener = new TransitionListenerAdapter() {
boolean mCanceled = false;
float mPausedAlpha;
@Override
public void onTransitionCancel(TransitionPort transition) {
endView.setAlpha(1);
mCanceled = true;
}
@Override
public void onTransitionEnd(TransitionPort transition) {
if (!mCanceled) {
endView.setAlpha(1);
}
}
@Override
public void onTransitionPause(TransitionPort transition) {
mPausedAlpha = endView.getAlpha();
endView.setAlpha(1);
}
@Override
public void onTransitionResume(TransitionPort transition) {
endView.setAlpha(mPausedAlpha);
}
};
addListener(transitionListener);
return createAnimation(endView, 0, 1, null);
}
@Override
public Animator onDisappear(ViewGroup sceneRoot,
TransitionValues startValues, int startVisibility,
TransitionValues endValues, int endVisibility) {
if ((mFadingMode & OUT) != OUT) {
return null;
}
View view = null;
View startView = (startValues != null) ? startValues.view : null;
View endView = (endValues != null) ? endValues.view : null;
if (DBG) {
Log.d(LOG_TAG, "Fade.onDisappear: startView, startVis, endView, endVis = " +
startView + ", " + startVisibility + ", " + endView + ", " + endVisibility);
}
View overlayView = null;
View viewToKeep = null;
if (endView == null || endView.getParent() == null) {
if (endView != null) {
// endView was removed from its parent - add it to the overlay
view = overlayView = endView;
} else if (startView != null) {
// endView does not exist. Use startView only under certain
// conditions, because placing a view in an overlay necessitates
// it being removed from its current parent
if (startView.getParent() == null) {
// no parent - safe to use
view = overlayView = startView;
} else if (startView.getParent() instanceof View &&
startView.getParent().getParent() == null) {
View startParent = (View) startView.getParent();
int id = startParent.getId();
if (id != View.NO_ID && sceneRoot.findViewById(id) != null && mCanRemoveViews) {
// no parent, but its parent is unparented but the parent
// hierarchy has been replaced by a new hierarchy with the same id
// and it is safe to un-parent startView
view = overlayView = startView;
}
}
}
} else {
// visibility change
if (endVisibility == View.INVISIBLE) {
view = endView;
viewToKeep = view;
} else {
// Becoming GONE
if (startView == endView) {
view = endView;
viewToKeep = view;
} else {
view = startView;
overlayView = view;
}
}
}
final int finalVisibility = endVisibility;
// TODO: add automatic facility to Visibility superclass for keeping views around
if (overlayView != null) {
// TODO: Need to do this for general case of adding to overlay
int screenX = (Integer) startValues.values.get(PROPNAME_SCREEN_X);
int screenY = (Integer) startValues.values.get(PROPNAME_SCREEN_Y);
int[] loc = new int[2];
sceneRoot.getLocationOnScreen(loc);
ViewCompat.offsetLeftAndRight(overlayView, (screenX - loc[0]) - overlayView.getLeft());
ViewCompat.offsetTopAndBottom(overlayView, (screenY - loc[1]) - overlayView.getTop());
ViewGroupOverlay.createFrom(sceneRoot).add(overlayView);
// sceneRoot.getOverlay().add(overlayView);
// TODO: add automatic facility to Visibility superclass for keeping views around
final float startAlpha = 1;
float endAlpha = 0;
final View finalView = view;
final View finalOverlayView = overlayView;
final View finalViewToKeep = viewToKeep;
final ViewGroup finalSceneRoot = sceneRoot;
final AnimatorListenerAdapter endListener = new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
finalView.setAlpha(startAlpha);
// TODO: restore view offset from overlay repositioning
if (finalViewToKeep != null) {
finalViewToKeep.setVisibility(finalVisibility);
}
if (finalOverlayView != null) {
ViewGroupOverlay.createFrom(finalSceneRoot).remove(finalOverlayView);
// finalSceneRoot.getOverlay().remove(finalOverlayView);
}
}
//
// @Override
// public void onAnimationPause(Animator animation) {
// if (finalOverlayView != null) {
// finalSceneRoot.getOverlay().remove(finalOverlayView);
// }
// }
//
// @Override
// public void onAnimationResume(Animator animation) {
// if (finalOverlayView != null) {
// finalSceneRoot.getOverlay().add(finalOverlayView);
// }
// }
};
return createAnimation(view, startAlpha, endAlpha, endListener);
}
if (viewToKeep != null) {
// TODO: find a different way to do this, like just changing the view to be
// VISIBLE for the duration of the transition
viewToKeep.setVisibility((View.VISIBLE));
// TODO: add automatic facility to Visibility superclass for keeping views around
final float startAlpha = 1;
float endAlpha = 0;
final View finalView = view;
final View finalOverlayView = overlayView;
final View finalViewToKeep = viewToKeep;
final ViewGroup finalSceneRoot = sceneRoot;
final AnimatorListenerAdapter endListener = new AnimatorListenerAdapter() {
boolean mCanceled = false;
float mPausedAlpha = -1;
// @Override
// public void onAnimationPause(Animator animation) {
// if (finalViewToKeep != null && !mCanceled) {
// finalViewToKeep.setVisibility(finalVisibility);
// }
// mPausedAlpha = finalView.getAlpha();
// finalView.setAlpha(startAlpha);
// }
//
// @Override
// public void onAnimationResume(Animator animation) {
// if (finalViewToKeep != null && !mCanceled) {
// finalViewToKeep.setVisibility(View.VISIBLE);
// }
// finalView.setAlpha(mPausedAlpha);
// }
@Override
public void onAnimationCancel(Animator animation) {
mCanceled = true;
if (mPausedAlpha >= 0) {
finalView.setAlpha(mPausedAlpha);
}
}
@Override
public void onAnimationEnd(Animator animation) {
if (!mCanceled) {
finalView.setAlpha(startAlpha);
}
// TODO: restore view offset from overlay repositioning
if (finalViewToKeep != null && !mCanceled) {
finalViewToKeep.setVisibility(finalVisibility);
}
if (finalOverlayView != null) {
ViewGroupOverlay.createFrom(finalSceneRoot).add(finalOverlayView);
// finalSceneRoot.getOverlay().remove(finalOverlayView);
}
}
};
return createAnimation(view, startAlpha, endAlpha, endListener);
}
return null;
}
}