Я пытаюсь реализовать сенсорный просмотр изображений - как в приложении «Галерея».Мне удалось это сделать, и он работает хорошо, за исключением того, что он ОЧЕНЬ запаздывает по сравнению с обычной галереей.
Я ищу способы сделать его более плавным.Вот что у меня сейчас:
@SuppressWarnings("unused")
public class ImageDisplayView extends ImageView {
private static final String TAG = "ImageDisplayView";
private static final int MODE_NONE = 0;
private static final int MODE_DRAG = 1;
private static final int MODE_ZOOM = 2;
// Zoom Bounds
private static final float SCALE_MIN = 0.8f;
private static final float SCALE_BOTTOM = 1.0f;
private static final float SCALE_TOP = 10.0f;
private static final float SCALE_MAX = 12.0f;
// Transformation
private Matrix mMatrix = new Matrix();
private Matrix mPreMatrix = new Matrix();
private PointF mPivot = new PointF();
private PointF mNewPivot = new PointF();
private float mDist;
// State
private boolean mInitialScaleDone = false;
private boolean mEnabled = true;
private RectF mBounds = new RectF();
private Float mScale = null;
private float mMode = MODE_NONE;
public ImageDisplayView(Context context) {
super(context);
initialScale();
}
public ImageDisplayView(Context context, AttributeSet attrs) {
super(context, attrs);
initialScale();
}
public ImageDisplayView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initialScale();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
initialScale();
}
private void initialScale() {
if (!mInitialScaleDone && getDrawable() != null) {
mInitialScaleDone = true;
final Runnable r = new Runnable() {
@Override
public void run() {
// Fit to screen
float scale = calculateFitScreenScale();
mMatrix.reset();
mMatrix.postScale(scale, scale);
setImageMatrix(mMatrix);
// Center
float dx = (getWidth() - mBounds.width()) / 2, dy = (getHeight() - mBounds
.height()) / 2;
mMatrix.postTranslate(dx, dy);
setImageMatrix(mMatrix);
mScale = 1.0f;
}
};
if (getWidth() == 0) {
getViewTreeObserver().addOnGlobalLayoutListener(
new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
r.run();
getViewTreeObserver()
.removeGlobalOnLayoutListener(this);
}
});
} else {
r.run();
}
}
}
@Override
public void setImageMatrix(Matrix matrix) {
super.setImageMatrix(matrix);
mBounds.set(getDrawable().getBounds());
matrix.mapRect(mBounds);
}
@Override
public void setEnabled(boolean enabled) {
mEnabled = enabled;
if (!enabled && mMode != MODE_NONE) {
if (mMode == MODE_DRAG) {
checkLimits(null);
} else {
mPivot.set(getWidth() / 2, getHeight() / 2);
updateScale();
mPreMatrix.set(mMatrix);
checkLimits(null);
}
mMode = MODE_NONE;
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float scale, dx, dy;
if (mEnabled) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_POINTER_DOWN:
if (event.getPointerCount() == 1) { // Start mode: drag only.
mMode = MODE_DRAG;
mPivot.set(event.getX(), event.getY());
} else { // Start mode: zoom and drag.
mMode = MODE_ZOOM;
mDist = distance(event);
midPoint(mPivot, event);
}
mPreMatrix.set(mMatrix);
return true;
case MotionEvent.ACTION_UP:
mMode = MODE_NONE;
checkLimits(event);
break;
case MotionEvent.ACTION_POINTER_UP:
if (event.getPointerCount() == 2) {
mMode = MODE_DRAG;
mPivot.set(event.getX(), event.getY());
updateScale();
mPreMatrix.set(mMatrix);
}
return true;
case MotionEvent.ACTION_MOVE:
mMatrix.set(mPreMatrix);
if (mMode == MODE_DRAG) {
dx = event.getX() - mPivot.x;
dy = event.getY() - mPivot.y;
mMatrix.postTranslate(dx, dy);
} else if (mMode == MODE_ZOOM) {
scale = distance(event) / mDist;
midPoint(mNewPivot, event);
dx = mNewPivot.x - mPivot.x;
dy = mNewPivot.y - mPivot.y;
mMatrix.postTranslate(dx, dy);
float postScale = mScale * scale;
if (postScale < SCALE_MIN) {
scale = SCALE_MIN / mScale;
} else if (postScale > SCALE_MAX) {
scale = SCALE_MAX / mScale;
}
mMatrix.postScale(scale, scale, mNewPivot.x, mNewPivot.y);
}
setImageMatrix(mMatrix);
return true;
}
}
return super.onTouchEvent(event);
}
private void updateScale() {
mScale = (mBounds.width() / getDrawable().getIntrinsicWidth())
/ calculateFitScreenScale();
}
@IntendedCaller("onTouchEvent(MotionEvent)")
private void checkLimits(MotionEvent event) {
float scale, dx, dy;
if (mScale < SCALE_BOTTOM) {
scale = SCALE_BOTTOM;
} else if (mScale > SCALE_TOP) {
scale = SCALE_TOP;
} else {
scale = mScale;
}
RectF scaleBounds = new RectF(mBounds); // Use the scale of the image
// to determine drag
// threshold.
scaleBounds.offset(getWidth() / 2 - scaleBounds.centerX(), getHeight()
/ 2 - scaleBounds.centerY());
dx = Math.min(0.0f, Math.max(0.0f, scaleBounds.left) - mBounds.left)
+ Math.max(0.0f, Math.min(getWidth(), scaleBounds.right)
- mBounds.right);
dy = Math.min(0.0f, Math.max(0.0f, scaleBounds.top) - mBounds.top)
+ Math.max(0.0f, Math.min(getHeight(), scaleBounds.bottom)
- mBounds.bottom);
animateTransformation(event, 500, null, scale, dx, dy);
}
public void animateTransformation(MotionEvent event, long duration,
final Runnable callback, final float targetScale, final float dx,
final float dy) {
mPreMatrix.set(mMatrix);
final float scale = targetScale / mScale;
final float px, py;
if (event != null) {
PointF pivot = new PointF();
midPoint(pivot, event);
px = scale > 1.0f ? mBounds.centerX() : dx > 0 ? mBounds.right
: dx < 0 ? mBounds.left : pivot.x;
py = scale > 1.0f ? mBounds.centerY() : dy > 0 ? mBounds.bottom
: dy < 0 ? mBounds.top : pivot.y;
} else {
px = mBounds.centerX();
py = mBounds.centerY();
}
Utils.animate(this, new Animator() {
@Override
public void onAnimationEnd() {
updateScale();
if (callback != null) {
callback.run();
}
}
@Override
public void makeStep(float percent) {
mMatrix.set(mPreMatrix);
float s = 1.0f + percent * (scale - 1.0f);
float tempx = dx * percent, tempy = dy * percent;
mMatrix.postTranslate(tempx, tempy);
mMatrix.postScale(s, s, px + tempx, py + tempy);
setImageMatrix(mMatrix);
}
}, duration);
}
public RectF getBounds() {
return mBounds;
}
public float getScale() {
return mScale;
}
public void scale(float scale, float px, float py) {
mMatrix.set(getImageMatrix());
mMatrix.postScale(scale, scale, px, py);
setImageMatrix(mMatrix);
mScale = scale;
}
public void translate(float dx, float dy) {
mMatrix.set(getImageMatrix());
mMatrix.postTranslate(dx, dy);
setImageMatrix(mMatrix);
}
public void resetAndCenter() {
mMatrix.set(getImageMatrix());
mMatrix.postScale(1 / mScale, 1 / mScale, mBounds.centerX(),
mBounds.centerY());
setImageMatrix(mMatrix);
// Center
float dx = (getWidth() - mBounds.width()) / 2, dy = (getHeight() - mBounds
.height()) / 2;
mMatrix.postTranslate(dx, dy);
setImageMatrix(mMatrix);
updateScale();
}
@Override
public void setImageBitmap(Bitmap bm) {
super.setImageBitmap(bm);
mInitialScaleDone = false;
initialScale();
}
private float distance(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}
private void midPoint(PointF p, MotionEvent event) {
if (event.getPointerCount() == 1) {
p.set(event.getX(), event.getY());
} else {
p.set((event.getX(1) + event.getX(0)) / 2,
(event.getY(1) + event.getY(0)) / 2);
}
}
private float calculateFitScreenScale() {
RectF r = new RectF(getDrawable().getBounds());
float w = getWidth(), h = getHeight();
if (r.width() > r.height()) {
return w / r.width();
} else if (r.width() == r.height()) {
if (w < h) {
return w / r.width();
} else {
return h / r.height();
}
} else {
return h / r.height();
}
}
}
Что я могу сделать, чтобы сделать это менее медленным?Любая помощь высоко ценится.