/**
* Wire
* Copyright (C) 2016 Wire Swiss GmbH
*
* This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.waz.zclient.pages.main.conversation.views.image;
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v4.view.ViewCompat;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.Interpolator;
import android.widget.FrameLayout;
import com.waz.zclient.ui.utils.MathUtils;
import com.waz.zclient.ui.animation.interpolators.penner.Cubic;
public class ImageDragViewContainer extends FrameLayout {
private static final float MAX_DISTANCE_SCALE_FACTOR = 1.5f;
private static final int MAX_ROTATION = 24;
private static final int MIN_ROTATION = 5;
private static final float FLING_DURATION_SECONDS = 0.05f;
private static final Interpolator DISTANCE_INTERPOLATOR = new Cubic.EaseIn();
private static final float NORMALIZED_FLING_DISTANCE_THRESHOLD = 0.3f;
private ImageDragViewHelper dragHelper;
private boolean enabled = true;
private ImageViewDragCallback imageViewDragCallback;
private Callback callback;
public ImageDragViewContainer(Context context) {
this(context, null);
}
public ImageDragViewContainer(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public ImageDragViewContainer(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
imageViewDragCallback = new ImageViewDragCallback();
}
@Override
protected void onAttachedToWindow() {
super.onAttachedToWindow();
dragHelper = ImageDragViewHelper.create(this, 1.0f, imageViewDragCallback);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
if (ev == null) {
return false;
}
if (ev.getPointerCount() != 1) {
return false;
}
boolean shouldDrag;
try {
shouldDrag = dragHelper.shouldInterceptTouchEvent(ev);
} catch (Exception e) {
return false;
}
if (ev.getAction() == MotionEvent.ACTION_DOWN) {
imageViewDragCallback.startX = ev.getX();
imageViewDragCallback.startY = ev.getY();
imageViewDragCallback.centerX = getLeft() + (getRight() - getLeft()) / 2f;
imageViewDragCallback.centerY = getTop() + (getBottom() - getTop()) / 2f;
}
boolean intercept = enabled && shouldDrag;
if (callback != null && intercept) {
callback.onStartDrag();
}
return intercept;
}
@Override
public boolean onTouchEvent(@NonNull MotionEvent ev) {
try {
dragHelper.processTouchEvent(ev);
} catch (Exception ignored) { }
return true;
}
@Override
public void computeScroll() {
super.computeScroll();
if (dragHelper.continueSettling(true)) {
ViewCompat.postInvalidateOnAnimation(this);
} else if (imageViewDragCallback.isFlinging) {
imageViewDragCallback.settled();
}
}
public void setDraggingEnabled(boolean enabled) {
this.enabled = enabled;
}
public void setCallback(Callback callback) {
this.callback = callback;
}
public interface Callback {
void onFlingRequested(float left, float top, float rotation, float pivotX, float pivotY);
void onDragDistance(float distance);
void onStartDrag();
void onEndDrag();
}
private class ImageViewDragCallback extends ImageDragViewHelper.Callback {
private float lastRotation;
public float centerX = 0;
public float centerY = 0;
public float startX = 0;
public float startY = 0;
public int x = 0;
public int y = 0;
private boolean isFlinging;
@Override
public boolean tryCaptureView(View view, int i) {
return true;
}
@Override
public int clampViewPositionVertical(View child, int top, int dy) {
return top;
}
@Override
public int getViewVerticalDragRange(View child) {
return child.getMeasuredHeight();
}
@Override
public void onViewReleased(View releasedChild, float xvel, float yvel) {
super.onViewReleased(releasedChild, xvel, yvel);
float normalizedDistance = getNormalizedDragDistance();
if (normalizedDistance > NORMALIZED_FLING_DISTANCE_THRESHOLD && callback != null) {
isFlinging = true;
dragHelper.settleCapturedViewAt(releasedChild.getLeft(),
(int) (releasedChild.getTop() + (yvel / 1.25f) * FLING_DURATION_SECONDS));
} else {
if (callback != null) {
callback.onEndDrag();
}
dragHelper.settleCapturedViewAt(0, 0);
}
postInvalidate();
}
private float getNormalizedDragDistance() {
return (float) MathUtils.clamp(Math.abs(y / (MAX_DISTANCE_SCALE_FACTOR * centerY)), 0, 1);
}
@Override
public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) {
super.onViewPositionChanged(changedView, left, top, dx, dy);
x += dx;
y -= dy;
float normalizedDistance = getNormalizedDragDistance();
if (callback != null) {
callback.onDragDistance(normalizedDistance);
}
changedView.setPivotX(startX);
changedView.setPivotY(startY);
float maxRotation = (float) (MAX_ROTATION * MathUtils.clamp(Math.abs(startX - centerX),
MIN_ROTATION / MAX_ROTATION,
1f));
changedView.setRotation(maxRotation * DISTANCE_INTERPOLATOR.getInterpolation(normalizedDistance) *
Math.signum(-y) * Math.signum(startX - centerX));
lastRotation = changedView.getRotation();
}
public void settled() {
isFlinging = false;
if (callback != null) {
callback.onFlingRequested(x,
-y,
lastRotation,
startX,
startY);
}
}
}
}