Files
Lawnchair/src/com/android/launcher3/folder/StackFolderIconLayoutRule.java
T
Sunny Goyal 828b11e5a9 Setting the callback for previewItems to folderIcon. This allows the FolderIcon to get updated
without going through the child'draw pass.
Also simplifying the draw code for the FolderIcon to remove any cycling invalidate calls

Bug: 62900800
Change-Id: I17009a5347a1c3c35426313ac759e0240ce6a395
2017-06-22 10:25:43 -07:00

103 lines
3.8 KiB
Java

/**
* Copyright (C) 2015 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 com.android.launcher3.folder;
import com.android.launcher3.folder.FolderIcon.PreviewItemDrawingParams;
public class StackFolderIconLayoutRule implements FolderIcon.PreviewLayoutRule {
static final int MAX_NUM_ITEMS_IN_PREVIEW = 3;
// The degree to which the item in the back of the stack is scaled [0...1]
// (0 means it's not scaled at all, 1 means it's scaled to nothing)
private static final float PERSPECTIVE_SCALE_FACTOR = 0.35f;
// The amount of vertical spread between items in the stack [0...1]
private static final float PERSPECTIVE_SHIFT_FACTOR = 0.18f;
private float mBaselineIconScale;
private int mBaselineIconSize;
private int mAvailableSpaceInPreview;
private float mMaxPerspectiveShift;
@Override
public void init(int availableSpace, float intrinsicIconSize, boolean rtl) {
mAvailableSpaceInPreview = availableSpace;
// cos(45) = 0.707 + ~= 0.1) = 0.8f
int adjustedAvailableSpace = (int) ((mAvailableSpaceInPreview / 2) * (1 + 0.8f));
int unscaledHeight = (int) (intrinsicIconSize * (1 + PERSPECTIVE_SHIFT_FACTOR));
mBaselineIconScale = (1.0f * adjustedAvailableSpace / unscaledHeight);
mBaselineIconSize = (int) (intrinsicIconSize * mBaselineIconScale);
mMaxPerspectiveShift = mBaselineIconSize * PERSPECTIVE_SHIFT_FACTOR;
}
@Override
public PreviewItemDrawingParams computePreviewItemDrawingParams(int index, int curNumItems,
PreviewItemDrawingParams params) {
float scale = scaleForItem(index, curNumItems);
index = MAX_NUM_ITEMS_IN_PREVIEW - index - 1;
float r = (index * 1.0f) / (MAX_NUM_ITEMS_IN_PREVIEW - 1);
float offset = (1 - r) * mMaxPerspectiveShift;
float scaledSize = scale * mBaselineIconSize;
float scaleOffsetCorrection = (1 - scale) * mBaselineIconSize;
// We want to imagine our coordinates from the bottom left, growing up and to the
// right. This is natural for the x-axis, but for the y-axis, we have to invert things.
float transY = mAvailableSpaceInPreview - (offset + scaledSize + scaleOffsetCorrection);
float transX = (mAvailableSpaceInPreview - scaledSize) / 2;
float totalScale = mBaselineIconScale * scale;
final float overlayAlpha = (80 * (1 - r)) / 255f;
if (params == null) {
params = new PreviewItemDrawingParams(transX, transY, totalScale, overlayAlpha);
} else {
params.update(transX, transY, totalScale);
params.overlayAlpha = overlayAlpha;
}
return params;
}
@Override
public int maxNumItems() {
return MAX_NUM_ITEMS_IN_PREVIEW;
}
@Override
public float getIconSize() {
return mBaselineIconSize;
}
@Override
public float scaleForItem(int index, int numItems) {
// Scale is determined by the position of the icon in the preview.
index = MAX_NUM_ITEMS_IN_PREVIEW - index - 1;
float r = (index * 1.0f) / (MAX_NUM_ITEMS_IN_PREVIEW - 1);
return (1 - PERSPECTIVE_SCALE_FACTOR * (1 - r));
}
@Override
public boolean clipToBackground() {
return false;
}
}