/**
* 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.conversationpager;
import android.support.annotation.IntDef;
import android.support.v4.view.ViewPager;
import android.view.View;
import com.waz.zclient.utils.ViewUtils;
public class CustomPagerTransformer implements ViewPager.PageTransformer {
@IntDef({FLOW,
DEPTH,
ZOOM,
SLIDE_OVER,
SLIDE_IN,
SLIDE
})
public @interface TransformType { }
public static final int FLOW = 0;
public static final int DEPTH = 1;
public static final int ZOOM = 2;
public static final int SLIDE_OVER = 3;
public static final int SLIDE_IN = 4;
public static final int SLIDE = 5;
@TransformType private final int transformType;
public CustomPagerTransformer(@TransformType int transformType) {
this.transformType = transformType;
}
private static final float MIN_SCALE_DEPTH = 0.75f;
private static final float MIN_SCALE_ZOOM = 0.85f;
private static final float MIN_ALPHA_ZOOM = 0.5f;
private static final float SCALE_FACTOR_SLIDE = 0.85f;
private static final float MIN_ALPHA_SLIDE = 0.35f;
public void transformPage(View page, float position) {
final float alpha;
final float scale;
final float translationX;
switch (transformType) {
case FLOW:
page.setRotationY(position * -30f);
return;
case SLIDE_OVER:
if (position < 0 && position > -1) {
// this is the page to the left
scale = Math.abs(Math.abs(position) - 1) * (1.0f - SCALE_FACTOR_SLIDE) + SCALE_FACTOR_SLIDE;
alpha = Math.max(MIN_ALPHA_SLIDE, 1 - Math.abs(position));
int pageWidth = page.getWidth();
float translateValue = position * (-pageWidth);
if (translateValue > -pageWidth) {
translationX = translateValue;
} else {
translationX = 0;
}
} else {
alpha = 1;
scale = 1;
translationX = 0;
}
break;
case SLIDE_IN:
if (position < 0 && position > -1) {
// this is the page to the left
scale = 1;
alpha = 1;
int pageWidth = page.getWidth();
float translateValue = position * -pageWidth + position * (-ViewUtils.toPx(page.getContext(), 64));
if (translateValue > -pageWidth) {
translationX = translateValue;
} else {
translationX = 0;
}
} else {
alpha = 1;
scale = 1;
translationX = 0;
}
break;
case DEPTH:
if (position > 0 && position < 1) {
// moving to the right
alpha = (1 - position);
scale = MIN_SCALE_DEPTH + (1 - MIN_SCALE_DEPTH) * (1 - Math.abs(position));
translationX = (page.getWidth() * -position);
} else {
// use default for all other cases
alpha = 1;
scale = 1;
translationX = 0;
}
break;
case ZOOM:
if (position >= -1 && position <= 1) {
scale = Math.max(MIN_SCALE_ZOOM, 1 - Math.abs(position));
alpha = MIN_ALPHA_ZOOM +
(scale - MIN_SCALE_ZOOM) / (1 - MIN_SCALE_ZOOM) * (1 - MIN_ALPHA_ZOOM);
float vMargin = page.getHeight() * (1 - scale) / 2;
float hMargin = page.getWidth() * (1 - scale) / 2;
if (position < 0) {
translationX = (hMargin - vMargin / 2);
} else {
translationX = (-hMargin + vMargin / 2);
}
} else {
alpha = 1;
scale = 1;
translationX = 0;
}
break;
case SLIDE:
alpha = 1;
scale = 1;
if (position >= -1 && position <= 1) {
float vMargin = page.getHeight() * (1 - scale) / 2;
float hMargin = page.getWidth() * (1 - scale) / 2;
if (position < 0) {
translationX = (hMargin - vMargin / 2);
} else {
translationX = (-hMargin + vMargin / 2);
}
} else {
translationX = 0;
}
break;
default:
return;
}
page.setAlpha(alpha);
page.setTranslationX(translationX);
page.setScaleX(scale);
page.setScaleY(scale);
}
}