private void fling(float vx, float vy) {
// 以修正动画为大，遇到修正动画正在执行，就不执行惯性动画
if (!(mScaleAnimator != null && mScaleAnimator.isRunning()) && getDrawable() != null) {
if (mFlingAnimator != null) {
mFlingAnimator.cancel();
mFlingAnimator = null;
}
mFlingAnimator = new FlingAnimator(new float[] {vx / 1000 * 16, vy / 1000 * 16});
mFlingAnimator.start();
}
}
public boolean animFromTo(Matrix matrixFrom, Matrix matrixTo) {
if (getDrawable() == null) {
return false;
}
if (mScaleAnimator != null) {
mScaleAnimator.cancel();
mScaleAnimator = null;
}
if (mFlingAnimator != null) {
mFlingAnimator.cancel();
mFlingAnimator = null;
}
mScaleAnimator = new ScaleAnimator(matrixFrom, matrixTo);
mScaleAnimator.start();
return true;
}
// 停止所有动画，重置位置到fit center状态
public void reset() {
mOuterMatrix = new Matrix();
onOuterMatrixChanged();
mPinchMode = PINCH_MODE_FREE;
mLastMovePoint = new PointF();
mScaleCenter = new PointF();
mScaleBase = 0;
if (mScaleAnimator != null) {
mScaleAnimator.cancel();
mScaleAnimator = null;
}
if (mFlingAnimator != null) {
mFlingAnimator.cancel();
mFlingAnimator = null;
}
invalidate();
}
// 当缩放操作结束如果不在正确位置用动画恢复
private void scaleEnd() {
// 不允许动画过程中再触发
if ((mScaleAnimator != null && mScaleAnimator.isRunning()) || getDrawable() == null) {
return;
}
// 是否修正了位置
boolean change = false;
// 获取图片整体的变换矩阵
Matrix currentMatrix = getCurrentImageMatrix();
// 整体缩放比例
float currentScale = MathUtils.getMatrixScale(currentMatrix)[0];
// 第二层缩放比例
float outerScale = MathUtils.getMatrixScale(mOuterMatrix)[0];
// 控件大小
float displayWidth = getMeasuredWidth();
float displayHeight = getMeasuredHeight();
float maxScale = getMaxScale();
// 比例修正
float scalePost = 1;
// 位置修正
float postX = 0;
float postY = 0;
// 如果整体缩放比例大于最大比例，进行缩放修正
if (currentScale > maxScale) {
scalePost = maxScale / currentScale;
}
// 如果缩放修正后整体导致第二层缩放小于1（就是图片比fit center状态还小），重新修正缩放
if (outerScale * scalePost < 1) {
scalePost = 1 / outerScale;
}
// 如果修正不为1，说明进行了修正
if (scalePost != 1) {
change = true;
}
// 尝试根据缩放点进行缩放修正
Matrix testMatrix = new Matrix(currentMatrix);
testMatrix.postScale(scalePost, scalePost, mLastMovePoint.x, mLastMovePoint.y);
RectF testBound =
new RectF(0, 0, getDrawable().getIntrinsicWidth(), getDrawable().getIntrinsicHeight());
// 获取缩放修正后的图片方框
testMatrix.mapRect(testBound);
// 检测缩放修正后位置有无超出，如果超出进行位置修正
if (testBound.right - testBound.left < displayWidth) {
postX = displayWidth / 2 - (testBound.right + testBound.left) / 2;
} else if (testBound.left > 0) {
postX = -testBound.left;
} else if (testBound.right < displayWidth) {
postX = displayWidth - testBound.right;
}
if (testBound.bottom - testBound.top < displayHeight) {
postY = displayHeight / 2 - (testBound.bottom + testBound.top) / 2;
} else if (testBound.top > 0) {
postY = -testBound.top;
} else if (testBound.bottom < displayHeight) {
postY = displayHeight - testBound.bottom;
}
// 如果位置修正不为0，说明进行了修正
if (postX != 0 || postY != 0) {
change = true;
}
// 只有有执行修正才执行动画
if (change) {
// 如果up的时候触发惯性，这里需要取消掉，以修正动画为主
if (mFlingAnimator != null) {
mFlingAnimator.cancel();
mFlingAnimator = null;
}
// 动画开始举证
Matrix animStart = new Matrix(mOuterMatrix);
// 计算结束举证
Matrix animEnd = new Matrix(mOuterMatrix);
animEnd.postScale(scalePost, scalePost, mLastMovePoint.x, mLastMovePoint.y);
animEnd.postTranslate(postX, postY);
// 启动矩阵动画
mScaleAnimator = new ScaleAnimator(animStart, animEnd);
mScaleAnimator.start();
}
}
// 双击后放大或者缩小
// 当当前缩放比例大于等于1，那么双击放大到MaxScale
// 当当前缩放比例小于1，双击放大到1
// 当当前缩放比例等于MaxScale，双击缩小到屏幕大小
private void doubleTap(float x, float y) {
// 不允许动画过程中再触发
if ((mScaleAnimator != null && mScaleAnimator.isRunning()) || getDrawable() == null) {
return;
}
// 获取第一层变换矩阵
Matrix innerMatrix = getInnerMatrix();
// 当前总的缩放比例
float innerScale = MathUtils.getMatrixScale(innerMatrix)[0];
float outerScale = MathUtils.getMatrixScale(mOuterMatrix)[0];
float currentScale = innerScale * outerScale;
// 控件大小
float displayWidth = getMeasuredWidth();
float displayHeight = getMeasuredHeight();
// 最大放大大小
float maxScale = getMaxScale();
// 接下来要放大的大小
float nextScale = calculateNextScale(innerScale, outerScale);
// 如果接下来放大大于最大值或者小于fit center值，则取边界
if (nextScale < innerScale) {
nextScale = innerScale;
} else if (nextScale > maxScale) {
nextScale = maxScale;
}
// 缩放动画初始矩阵为当前矩阵值
Matrix animStart = new Matrix(mOuterMatrix);
// 开始计算缩放动画的结果矩阵
Matrix animEnd = new Matrix(mOuterMatrix);
// 计算还需缩放的倍数
animEnd.postScale(nextScale / currentScale, nextScale / currentScale, x, y);
// 将放大点移动到控件中心
animEnd.postTranslate(displayWidth / 2 - x, displayHeight / 2 - y);
// 得到放大之后的图片方框
Matrix testMatrix = new Matrix(innerMatrix);
testMatrix.postConcat(animEnd);
RectF testBound =
new RectF(0, 0, getDrawable().getIntrinsicWidth(), getDrawable().getIntrinsicHeight());
testMatrix.mapRect(testBound);
// 修正位置
float postX = 0;
float postY = 0;
if (testBound.right - testBound.left < displayWidth) {
postX = displayWidth / 2 - (testBound.right + testBound.left) / 2;
} else if (testBound.left > 0) {
postX = -testBound.left;
} else if (testBound.right < displayWidth) {
postX = displayWidth - testBound.right;
}
if (testBound.bottom - testBound.top < displayHeight) {
postY = displayHeight / 2 - (testBound.bottom + testBound.top) / 2;
} else if (testBound.top > 0) {
postY = -testBound.top;
} else if (testBound.bottom < displayHeight) {
postY = displayHeight - testBound.bottom;
}
// 应用修正位置
animEnd.postTranslate(postX, postY);
// 如果正在执行惯性动画，则取消掉
if (mFlingAnimator != null) {
mFlingAnimator.cancel();
mFlingAnimator = null;
}
// 启动矩阵动画
mScaleAnimator = new ScaleAnimator(animStart, animEnd);
mScaleAnimator.start();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
super.onTouchEvent(event);
if (mPinchMode == PINCH_MODE_NO_PINCH) {
return true;
}
// 无论如何都处理各种外部手势
mGestureDetector.onTouchEvent(event);
int action = event.getAction() & MotionEvent.ACTION_MASK;
// 最后一个点抬起或者取消，结束所有模式
if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) {
if (mPinchMode == PINCH_MODE_SCALE) {
scaleEnd();
}
mPinchMode = PINCH_MODE_FREE;
} else if (action == MotionEvent.ACTION_POINTER_UP) {
if (mPinchMode == PINCH_MODE_SCALE) {
// 抬起的点如果大于2，那么缩放模式还有效，但是有可能初始点变了，重新测量初始点
if (event.getPointerCount() > 2) {
// 如果还没结束缩放模式，但是第一个点抬起了，那么让第二个点和第三个点作为缩放控制点
if (event.getAction() >> 8 == 0) {
saveScaleContext(event.getX(1), event.getY(1), event.getX(2), event.getY(2));
// 如果还没结束缩放模式，但是第二个点抬起了，那么让第一个点和第三个点作为缩放控制点
} else if (event.getAction() >> 8 == 1) {
saveScaleContext(event.getX(0), event.getY(0), event.getX(2), event.getY(2));
}
}
}
// 第一个点按下，开启滚动模式，记录开始滚动的点
} else if (action == MotionEvent.ACTION_DOWN) {
// 在矩阵动画过程中不允许启动滚动模式
if (!(mScaleAnimator != null && mScaleAnimator.isRunning())) {
// 停止惯性滚动
if (mFlingAnimator != null) {
mFlingAnimator.cancel();
mFlingAnimator = null;
}
mPinchMode = PINCH_MODE_SCROLL;
mLastMovePoint.set(event.getX(), event.getY());
}
// 非第一个点按下，关闭滚动模式，开启缩放模式，记录缩放模式的一些初始数据
} else if (action == MotionEvent.ACTION_POINTER_DOWN) {
// 停止惯性滚动
if (mFlingAnimator != null) {
mFlingAnimator.cancel();
mFlingAnimator = null;
}
// 停止矩阵动画
if (mScaleAnimator != null) {
mScaleAnimator.cancel();
mScaleAnimator = null;
}
mPinchMode = PINCH_MODE_SCALE;
saveScaleContext(event.getX(0), event.getY(0), event.getX(1), event.getY(1));
} else if (action == MotionEvent.ACTION_MOVE) {
if (!(mScaleAnimator != null && mScaleAnimator.isRunning())) {
// 在滚动模式下移动
if (mPinchMode == PINCH_MODE_SCROLL) {
// 每次移动产生一个差值累积到图片位置上
scrollBy(event.getX() - mLastMovePoint.x, event.getY() - mLastMovePoint.y);
// 记录新的移动点
mLastMovePoint.set(event.getX(), event.getY());
// 在缩放模式下移动
} else if (mPinchMode == PINCH_MODE_SCALE && event.getPointerCount() > 1) {
// 两个缩放点间的距离
float distance =
MathUtils.getDistance(event.getX(0), event.getY(0), event.getX(1), event.getY(1));
// 保存缩放点中点
float[] lineCenter =
MathUtils.getCenterPoint(event.getX(0), event.getY(0), event.getX(1), event.getY(1));
mLastMovePoint.set(lineCenter[0], lineCenter[1]);
// 处理缩放
scale(mScaleCenter, mScaleBase, distance, mLastMovePoint);
}
}
}
return true;
}
