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A library jar that provides APIs for Applications written for the Google Android Platform.
/*
* Copyright (C) 2020 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.internal.policy;
import android.annotation.IntDef;
import android.graphics.Point;
import android.graphics.Rect;
import com.android.internal.annotations.VisibleForTesting;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
/**
* Given a move coordinate (x, y), the original taks bounds and relevant details, calculate the new
* bounds.
*
* @hide
*/
public class TaskResizingAlgorithm {
@IntDef(flag = true,
value = {
CTRL_NONE,
CTRL_LEFT,
CTRL_RIGHT,
CTRL_TOP,
CTRL_BOTTOM
})
@Retention(RetentionPolicy.SOURCE)
public @interface CtrlType {}
public static final int CTRL_NONE = 0x0;
public static final int CTRL_LEFT = 0x1;
public static final int CTRL_RIGHT = 0x2;
public static final int CTRL_TOP = 0x4;
public static final int CTRL_BOTTOM = 0x8;
// The minimal aspect ratio which needs to be met to count as landscape (or 1/.. for portrait).
@VisibleForTesting
public static final float MIN_ASPECT = 1.2f;
/**
* Given a (x, y) point and its original starting down point and its original bounds, calculate
* and return a new resized bound.
* @param x the new moved X point.
* @param y the new moved Y point.
* @param startDragX the original starting X point.
* @param startDragY the original starting Y point.
* @param originalBounds the original bound before resize.
* @param ctrlType The type of resize operation.
* @param minVisibleWidth The minimal width required for the new size.
* @param minVisibleHeight The minimal height required for the new size.
* @param maxVisibleSize The maximum size allowed.
* @param preserveOrientation
* @param startOrientationWasLandscape
* @return
*/
public static Rect resizeDrag(float x, float y, float startDragX, float startDragY,
Rect originalBounds, int ctrlType, int minVisibleWidth, int minVisibleHeight,
Point maxVisibleSize, boolean preserveOrientation,
boolean startOrientationWasLandscape) {
// This is a resizing operation.
// We need to keep various constraints:
// 1. mMinVisible[Width/Height] <= [width/height] <= mMaxVisibleSize.[x/y]
// 2. The orientation is kept - if required.
final int deltaX = Math.round(x - startDragX);
final int deltaY = Math.round(y - startDragY);
int left = originalBounds.left;
int top = originalBounds.top;
int right = originalBounds.right;
int bottom = originalBounds.bottom;
// Calculate the resulting width and height of the drag operation.
int width = right - left;
int height = bottom - top;
if ((ctrlType & CTRL_LEFT) != 0) {
width = Math.max(minVisibleWidth, Math.min(width - deltaX, maxVisibleSize.x));
} else if ((ctrlType & CTRL_RIGHT) != 0) {
width = Math.max(minVisibleWidth, Math.min(width + deltaX, maxVisibleSize.x));
}
if ((ctrlType & CTRL_TOP) != 0) {
height = Math.max(minVisibleHeight, Math.min(height - deltaY, maxVisibleSize.y));
} else if ((ctrlType & CTRL_BOTTOM) != 0) {
height = Math.max(minVisibleHeight, Math.min(height + deltaY, maxVisibleSize.y));
}
// If we have to preserve the orientation - check that we are doing so.
final float aspect = (float) width / (float) height;
if (preserveOrientation && ((startOrientationWasLandscape && aspect < MIN_ASPECT)
|| (!startOrientationWasLandscape && aspect > (1.0 / MIN_ASPECT)))) {
// Calculate 2 rectangles fulfilling all requirements for either X or Y being the major
// drag axis. What ever is producing the bigger rectangle will be chosen.
int width1;
int width2;
int height1;
int height2;
if (startOrientationWasLandscape) {
// Assuming that the width is our target we calculate the height.
width1 = Math.max(minVisibleWidth, Math.min(maxVisibleSize.x, width));
height1 = Math.min(height, Math.round((float) width1 / MIN_ASPECT));
if (height1 < minVisibleHeight) {
// If the resulting height is too small we adjust to the minimal size.
height1 = minVisibleHeight;
width1 = Math.max(minVisibleWidth,
Math.min(maxVisibleSize.x, Math.round((float) height1 * MIN_ASPECT)));
}
// Assuming that the height is our target we calculate the width.
height2 = Math.max(minVisibleHeight, Math.min(maxVisibleSize.y, height));
width2 = Math.max(width, Math.round((float) height2 * MIN_ASPECT));
if (width2 < minVisibleWidth) {
// If the resulting width is too small we adjust to the minimal size.
width2 = minVisibleWidth;
height2 = Math.max(minVisibleHeight,
Math.min(maxVisibleSize.y, Math.round((float) width2 / MIN_ASPECT)));
}
} else {
// Assuming that the width is our target we calculate the height.
width1 = Math.max(minVisibleWidth, Math.min(maxVisibleSize.x, width));
height1 = Math.max(height, Math.round((float) width1 * MIN_ASPECT));
if (height1 < minVisibleHeight) {
// If the resulting height is too small we adjust to the minimal size.
height1 = minVisibleHeight;
width1 = Math.max(minVisibleWidth,
Math.min(maxVisibleSize.x, Math.round((float) height1 / MIN_ASPECT)));
}
// Assuming that the height is our target we calculate the width.
height2 = Math.max(minVisibleHeight, Math.min(maxVisibleSize.y, height));
width2 = Math.min(width, Math.round((float) height2 / MIN_ASPECT));
if (width2 < minVisibleWidth) {
// If the resulting width is too small we adjust to the minimal size.
width2 = minVisibleWidth;
height2 = Math.max(minVisibleHeight,
Math.min(maxVisibleSize.y, Math.round((float) width2 * MIN_ASPECT)));
}
}
// Use the bigger of the two rectangles if the major change was positive, otherwise
// do the opposite.
final boolean grows = width > (right - left) || height > (bottom - top);
if (grows == (width1 * height1 > width2 * height2)) {
width = width1;
height = height1;
} else {
width = width2;
height = height2;
}
}
// Generate the final bounds by keeping the opposite drag edge constant.
if ((ctrlType & CTRL_LEFT) != 0) {
left = right - width;
} else { // Note: The right might have changed - if we pulled at the right or not.
right = left + width;
}
if ((ctrlType & CTRL_TOP) != 0) {
top = bottom - height;
} else { // Note: The height might have changed - if we pulled at the bottom or not.
bottom = top + height;
}
return new Rect(left, top, right, bottom);
}
}
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