/*
* Copyright (C) 2014 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.transition;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Matrix;
import android.graphics.Path;
import android.graphics.PathMeasure;
import android.util.AttributeSet;
import android.util.PathParser;
import com.android.internal.R;
A PathMotion that takes a Path pattern and applies it to the separation between two points.
The starting point of the Path will be moved to the origin and the end point will be scaled
and rotated so that it matches with the target end point.
This may be used in XML as an element inside a transition.
<changeBounds>
<patternPathMotion android:patternPathData="M0 0 L0 100 L100 100"/>
</changeBounds>
/**
* A PathMotion that takes a Path pattern and applies it to the separation between two points.
* The starting point of the Path will be moved to the origin and the end point will be scaled
* and rotated so that it matches with the target end point.
* <p>This may be used in XML as an element inside a transition.</p>
* <pre>{@code
* <changeBounds>
* <patternPathMotion android:patternPathData="M0 0 L0 100 L100 100"/>
* </changeBounds>}
* </pre>
*/
public class PatternPathMotion extends PathMotion {
private Path mOriginalPatternPath;
private final Path mPatternPath = new Path();
private final Matrix mTempMatrix = new Matrix();
Constructs a PatternPathMotion with a straight-line pattern.
/**
* Constructs a PatternPathMotion with a straight-line pattern.
*/
public PatternPathMotion() {
mPatternPath.lineTo(1, 0);
mOriginalPatternPath = mPatternPath;
}
public PatternPathMotion(Context context, AttributeSet attrs) {
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.PatternPathMotion);
try {
String pathData = a.getString(R.styleable.PatternPathMotion_patternPathData);
if (pathData == null) {
throw new RuntimeException("pathData must be supplied for patternPathMotion");
}
Path pattern = PathParser.createPathFromPathData(pathData);
setPatternPath(pattern);
} finally {
a.recycle();
}
}
Creates a PatternPathMotion with the Path defining a pattern of motion between two
coordinates. The pattern will be translated, rotated, and scaled to fit between the start
and end points. The pattern must not be empty and must have the end point differ from the
start point.
Params: - patternPath – A Path to be used as a pattern for two-dimensional motion.
/**
* Creates a PatternPathMotion with the Path defining a pattern of motion between two
* coordinates. The pattern will be translated, rotated, and scaled to fit between the start
* and end points. The pattern must not be empty and must have the end point differ from the
* start point.
*
* @param patternPath A Path to be used as a pattern for two-dimensional motion.
*/
public PatternPathMotion(Path patternPath) {
setPatternPath(patternPath);
}
Returns the Path defining a pattern of motion between two coordinates.
The pattern will be translated, rotated, and scaled to fit between the start and end points.
The pattern must not be empty and must have the end point differ from the start point.
Returns: the Path defining a pattern of motion between two coordinates. @attr ref android.R.styleable#PatternPathMotion_patternPathData
/**
* Returns the Path defining a pattern of motion between two coordinates.
* The pattern will be translated, rotated, and scaled to fit between the start and end points.
* The pattern must not be empty and must have the end point differ from the start point.
*
* @return the Path defining a pattern of motion between two coordinates.
* @attr ref android.R.styleable#PatternPathMotion_patternPathData
*/
public Path getPatternPath() {
return mOriginalPatternPath;
}
Sets the Path defining a pattern of motion between two coordinates.
The pattern will be translated, rotated, and scaled to fit between the start and end points.
The pattern must not be empty and must have the end point differ from the start point.
Params: - patternPath – A Path to be used as a pattern for two-dimensional motion.
@attr ref android.R.styleable#PatternPathMotion_patternPathData
/**
* Sets the Path defining a pattern of motion between two coordinates.
* The pattern will be translated, rotated, and scaled to fit between the start and end points.
* The pattern must not be empty and must have the end point differ from the start point.
*
* @param patternPath A Path to be used as a pattern for two-dimensional motion.
* @attr ref android.R.styleable#PatternPathMotion_patternPathData
*/
public void setPatternPath(Path patternPath) {
PathMeasure pathMeasure = new PathMeasure(patternPath, false);
float length = pathMeasure.getLength();
float[] pos = new float[2];
pathMeasure.getPosTan(length, pos, null);
float endX = pos[0];
float endY = pos[1];
pathMeasure.getPosTan(0, pos, null);
float startX = pos[0];
float startY = pos[1];
if (startX == endX && startY == endY) {
throw new IllegalArgumentException("pattern must not end at the starting point");
}
mTempMatrix.setTranslate(-startX, -startY);
float dx = endX - startX;
float dy = endY - startY;
float distance = (float) Math.hypot(dx, dy);
float scale = 1 / distance;
mTempMatrix.postScale(scale, scale);
double angle = Math.atan2(dy, dx);
mTempMatrix.postRotate((float) Math.toDegrees(-angle));
patternPath.transform(mTempMatrix, mPatternPath);
mOriginalPatternPath = patternPath;
}
@Override
public Path getPath(float startX, float startY, float endX, float endY) {
double dx = endX - startX;
double dy = endY - startY;
float length = (float) Math.hypot(dx, dy);
double angle = Math.atan2(dy, dx);
mTempMatrix.setScale(length, length);
mTempMatrix.postRotate((float) Math.toDegrees(angle));
mTempMatrix.postTranslate(startX, startY);
Path path = new Path();
mPatternPath.transform(mTempMatrix, path);
return path;
}
}