/*
* TouchImageView.java
* By: Michael Ortiz
* Updated By: Patrick Lackemacher
* Updated By: Babay88
* Updated By: @ipsilondev
* -------------------
* Extends Android ImageView to include pinch zooming, panning, fling and double tap zoom.
*
* Copyright (c) 2012 Michael Ortiz
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
* The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE
*/
package ca.psiphon.ploggy.widgets;
import static ca.psiphon.ploggy.widgets.TouchImageView.State.ANIMATE_ZOOM;
import static ca.psiphon.ploggy.widgets.TouchImageView.State.DRAG;
import static ca.psiphon.ploggy.widgets.TouchImageView.State.FLING;
import static ca.psiphon.ploggy.widgets.TouchImageView.State.NONE;
import static ca.psiphon.ploggy.widgets.TouchImageView.State.ZOOM;
import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.os.Build.VERSION;
import android.os.Build.VERSION_CODES;
import android.os.Bundle;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.widget.ImageView;
import android.widget.Scroller;
public class TouchImageView extends ImageView {
private static final String DEBUG = "DEBUG";
//
// SuperMin and SuperMax multipliers. Determine how much the image can be
// zoomed below or above the zoom boundaries, before animating back to the
// min/max zoom boundary.
//
private static final float SUPER_MIN_MULTIPLIER = .75f;
private static final float SUPER_MAX_MULTIPLIER = 1.25f;
//
// Scale of image ranges from minScale to maxScale, where minScale == 1
// when the image is stretched to fit view.
//
private float normalizedScale;
//
// Matrix applied to image. MSCALE_X and MSCALE_Y should always be equal.
// MTRANS_X and MTRANS_Y are the other values used. prevMatrix is the matrix
// saved prior to the screen rotating.
//
private Matrix matrix, prevMatrix;
public static enum State { NONE, DRAG, ZOOM, FLING, ANIMATE_ZOOM };
private State state;
private float minScale;
private float maxScale;
private float superMinScale;
private float superMaxScale;
private float[] m;
private Context context;
private Fling fling;
//
// Size of view and previous view size (ie before rotation)
//
private int viewWidth, viewHeight, prevViewWidth, prevViewHeight;
//
// Size of image when it is stretched to fit view. Before and After rotation.
//
private float matchViewWidth, matchViewHeight, prevMatchViewWidth, prevMatchViewHeight;
private ScaleGestureDetector mScaleDetector;
private GestureDetector mGestureDetector;
public TouchImageView(Context context) {
super(context);
sharedConstructing(context);
}
public TouchImageView(Context context, AttributeSet attrs) {
super(context, attrs);
sharedConstructing(context);
}
public TouchImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
sharedConstructing(context);
}
private void sharedConstructing(Context context) {
super.setClickable(true);
this.context = context;
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
mGestureDetector = new GestureDetector(context, new GestureListener());
matrix = new Matrix();
prevMatrix = new Matrix();
m = new float[9];
normalizedScale = 1;
minScale = 1;
maxScale = 3;
superMinScale = SUPER_MIN_MULTIPLIER * minScale;
superMaxScale = SUPER_MAX_MULTIPLIER * maxScale;
setImageMatrix(matrix);
setScaleType(ScaleType.MATRIX);
setState(NONE);
setOnTouchListener(new TouchImageViewListener());
}
@Override
public Parcelable onSaveInstanceState() {
Bundle bundle = new Bundle();
bundle.putParcelable("instanceState", super.onSaveInstanceState());
bundle.putFloat("saveScale", normalizedScale);
bundle.putFloat("matchViewHeight", matchViewHeight);
bundle.putFloat("matchViewWidth", matchViewWidth);
bundle.putInt("viewWidth", viewWidth);
bundle.putInt("viewHeight", viewHeight);
matrix.getValues(m);
bundle.putFloatArray("matrix", m);
return bundle;
}
@Override
public void onRestoreInstanceState(Parcelable state) {
if (state instanceof Bundle) {
Bundle bundle = (Bundle) state;
normalizedScale = bundle.getFloat("saveScale");
m = bundle.getFloatArray("matrix");
prevMatrix.setValues(m);
prevMatchViewHeight = bundle.getFloat("matchViewHeight");
prevMatchViewWidth = bundle.getFloat("matchViewWidth");
prevViewHeight = bundle.getInt("viewHeight");
prevViewWidth = bundle.getInt("viewWidth");
super.onRestoreInstanceState(bundle.getParcelable("instanceState"));
return;
}
super.onRestoreInstanceState(state);
}
/**
* Set the max zoom multiplier. Default value: 3.
* @param max max zoom multiplier.
*/
public void setMaxZoom(float max) {
maxScale = max;
superMaxScale = SUPER_MAX_MULTIPLIER * maxScale;
}
/**
* Set the min zoom multiplier. Default value: 1.
* @param min min zoom multiplier.
*/
public void setMinZoom(float min) {
minScale = min;
superMinScale = SUPER_MIN_MULTIPLIER * minScale;
}
/**
* For a given point on the view (ie, a touch event), returns the
* point relative to the original drawable's coordinate system.
* @param x
* @param y
* @return PointF relative to original drawable's coordinate system.
*/
public PointF getDrawablePointFromTouchPoint(float x, float y) {
return transformCoordTouchToBitmap(x, y, true);
}
/**
* For a given point on the view (ie, a touch event), returns the
* point relative to the original drawable's coordinate system.
* @param p
* @return PointF relative to original drawable's coordinate system.
*/
public PointF getDrawablePointFromTouchPoint(PointF p) {
return transformCoordTouchToBitmap(p.x, p.y, true);
}
/**
* Performs boundary checking and fixes the image matrix if it
* is out of bounds.
*/
private void fixTrans() {
matrix.getValues(m);
float transX = m[Matrix.MTRANS_X];
float transY = m[Matrix.MTRANS_Y];
float fixTransX = getFixTrans(transX, viewWidth, getImageWidth());
float fixTransY = getFixTrans(transY, viewHeight, getImageHeight());
if (fixTransX != 0 || fixTransY != 0) {
matrix.postTranslate(fixTransX, fixTransY);
}
}
/**
* When transitioning from zooming from focus to zoom from center (or vice versa)
* the image can become unaligned within the view. This is apparent when zooming
* quickly. When the content size is less than the view size, the content will often
* be centered incorrectly within the view. fixScaleTrans first calls fixTrans() and
* then makes sure the image is centered correctly within the view.
*/
private void fixScaleTrans() {
fixTrans();
matrix.getValues(m);
if (getImageWidth() < viewWidth) {
m[Matrix.MTRANS_X] = (viewWidth - getImageWidth()) / 2;
}
if (getImageHeight() < viewHeight) {
m[Matrix.MTRANS_Y] = (viewHeight - getImageHeight()) / 2;
}
matrix.setValues(m);
}
private float getFixTrans(float trans, float viewSize, float contentSize) {
float minTrans, maxTrans;
if (contentSize <= viewSize) {
minTrans = 0;
maxTrans = viewSize - contentSize;
} else {
minTrans = viewSize - contentSize;
maxTrans = 0;
}
if (trans < minTrans) {
return -trans + minTrans;
}
if (trans > maxTrans) {
return -trans + maxTrans;
}
return 0;
}
private float getFixDragTrans(float delta, float viewSize, float contentSize) {
if (contentSize <= viewSize) {
return 0;
}
return delta;
}
private float getImageWidth() {
return matchViewWidth * normalizedScale;
}
private float getImageHeight() {
return matchViewHeight * normalizedScale;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Drawable drawable = getDrawable();
if (drawable == null || drawable.getIntrinsicWidth() == 0 || drawable.getIntrinsicHeight() == 0) {
return;
}
int drawableWidth = drawable.getIntrinsicWidth();
int drawableHeight = drawable.getIntrinsicHeight();
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
viewWidth = setViewSize(widthMode, widthSize, drawableWidth);
viewHeight = setViewSize(heightMode, heightSize, drawableHeight);
//
// Set view dimensions
//
setMeasuredDimension(viewWidth, viewHeight);
//
// Scale image for view
//
float scaleX = (float) viewWidth / drawableWidth;
float scaleY = (float) viewHeight / drawableHeight;
float scale = Math.min(scaleX, scaleY);
//
// Center the image
//
float redundantYSpace = viewHeight - (scale * drawableHeight);
float redundantXSpace = viewWidth - (scale * drawableWidth);
matchViewWidth = viewWidth - redundantXSpace;
matchViewHeight = viewHeight - redundantYSpace;
if (normalizedScale == 1) {
//
// Stretch and center image to fit view
//
matrix.setScale(scale, scale);
matrix.postTranslate(redundantXSpace / 2, redundantYSpace / 2);
} else {
prevMatrix.getValues(m);
//
// Rescale Matrix after rotation
//
m[Matrix.MSCALE_X] = matchViewWidth / drawableWidth * normalizedScale;
m[Matrix.MSCALE_Y] = matchViewHeight / drawableHeight * normalizedScale;
//
// TransX and TransY from previous matrix
//
float transX = m[Matrix.MTRANS_X];
float transY = m[Matrix.MTRANS_Y];
//
// Width
//
float prevActualWidth = prevMatchViewWidth * normalizedScale;
float actualWidth = getImageWidth();
translateMatrixAfterRotate(Matrix.MTRANS_X, transX, prevActualWidth, actualWidth, prevViewWidth, viewWidth, drawableWidth);
//
// Height
//
float prevActualHeight = prevMatchViewHeight * normalizedScale;
float actualHeight = getImageHeight();
translateMatrixAfterRotate(Matrix.MTRANS_Y, transY, prevActualHeight, actualHeight, prevViewHeight, viewHeight, drawableHeight);
//
// Set the matrix to the adjusted scale and translate values.
//
matrix.setValues(m);
}
fixTrans();
setImageMatrix(matrix);
}
/**
* Set view dimensions based on layout params
*
* @param mode
* @param size
* @param drawableWidth
* @return
*/
private int setViewSize(int mode, int size, int drawableWidth) {
int viewSize;
switch (mode) {
case MeasureSpec.EXACTLY:
viewSize = size;
break;
case MeasureSpec.AT_MOST:
viewSize = Math.min(drawableWidth, size);
break;
case MeasureSpec.UNSPECIFIED:
viewSize = drawableWidth;
break;
default:
viewSize = size;
break;
}
return viewSize;
}
/**
* After rotating, the matrix needs to be translated. This function finds the area of image
* which was previously centered and adjusts translations so that is again the center, post-rotation.
*
* @param axis Matrix.MTRANS_X or Matrix.MTRANS_Y
* @param trans the value of trans in that axis before the rotation
* @param prevImageSize the width/height of the image before the rotation
* @param imageSize width/height of the image after rotation
* @param prevViewSize width/height of view before rotation
* @param viewSize width/height of view after rotation
* @param drawableSize width/height of drawable
*/
private void translateMatrixAfterRotate(int axis, float trans, float prevImageSize, float imageSize, int prevViewSize, int viewSize, int drawableSize) {
if (imageSize < viewSize) {
//
// The width/height of image is less than the view's width/height. Center it.
//
m[axis] = (viewSize - (drawableSize * m[Matrix.MSCALE_X])) * 0.5f;
} else if (trans > 0) {
//
// The image is larger than the view, but was not before rotation. Center it.
//
m[axis] = -((imageSize - viewSize) * 0.5f);
} else {
//
// Find the area of the image which was previously centered in the view. Determine its distance
// from the left/top side of the view as a fraction of the entire image's width/height. Use that percentage
// to calculate the trans in the new view width/height.
//
float percentage = (Math.abs(trans) + (0.5f * prevViewSize)) / prevImageSize;
m[axis] = -((percentage * imageSize) - (viewSize * 0.5f));
}
}
private void setState(State state) {
this.state = state;
}
/**
* Gesture Listener detects a single click or long click and passes that on
* to the view's listener.
* @author Ortiz
*
*/
private class GestureListener extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onSingleTapConfirmed(MotionEvent e)
{
return performClick();
}
@Override
public void onLongPress(MotionEvent e)
{
performLongClick();
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)
{
if (fling != null) {
//
// If a previous fling is still active, it should be cancelled so that two flings
// are not run simultaenously.
//
fling.cancelFling();
}
fling = new Fling((int) velocityX, (int) velocityY);
compatPostOnAnimation(fling);
return super.onFling(e1, e2, velocityX, velocityY);
}
@Override
public boolean onDoubleTap(MotionEvent e) {
boolean consumed = false;
if (state == NONE) {
float targetZoom = (normalizedScale == minScale) ? maxScale : minScale;
DoubleTapZoom doubleTap = new DoubleTapZoom(normalizedScale, targetZoom, e.getX(), e.getY(), false);
compatPostOnAnimation(doubleTap);
consumed = true;
}
return consumed;
}
}
/**
* Responsible for all touch events. Handles the heavy lifting of drag and also sends
* touch events to Scale Detector and Gesture Detector.
* @author Ortiz
*
*/
private class TouchImageViewListener implements OnTouchListener {
//
// Remember last point position for dragging
//
private final PointF last = new PointF();
@Override
public boolean onTouch(View v, MotionEvent event) {
mScaleDetector.onTouchEvent(event);
mGestureDetector.onTouchEvent(event);
PointF curr = new PointF(event.getX(), event.getY());
if (state == NONE || state == DRAG || state == FLING) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
last.set(curr);
if (fling != null) {
fling.cancelFling();
}
setState(DRAG);
break;
case MotionEvent.ACTION_MOVE:
if (state == DRAG) {
float deltaX = curr.x - last.x;
float deltaY = curr.y - last.y;
float fixTransX = getFixDragTrans(deltaX, viewWidth, getImageWidth());
float fixTransY = getFixDragTrans(deltaY, viewHeight, getImageHeight());
matrix.postTranslate(fixTransX, fixTransY);
fixTrans();
last.set(curr.x, curr.y);
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
setState(NONE);
break;
}
}
setImageMatrix(matrix);
invalidate();
//
// indicate event was handled
//
return true;
}
}
/**
* ScaleListener detects user two finger scaling and scales image.
* @author Ortiz
*
*/
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
setState(ZOOM);
return true;
}
@Override
public boolean onScale(ScaleGestureDetector detector) {
scaleImage(detector.getScaleFactor(), detector.getFocusX(), detector.getFocusY(), true);
return true;
}
@Override
public void onScaleEnd(ScaleGestureDetector detector) {
super.onScaleEnd(detector);
setState(NONE);
boolean animateToZoomBoundary = false;
float targetZoom = normalizedScale;
if (normalizedScale > maxScale) {
targetZoom = maxScale;
animateToZoomBoundary = true;
} else if (normalizedScale < minScale) {
targetZoom = minScale;
animateToZoomBoundary = true;
}
if (animateToZoomBoundary) {
DoubleTapZoom doubleTap = new DoubleTapZoom(normalizedScale, targetZoom, viewWidth / 2, viewHeight / 2, true);
compatPostOnAnimation(doubleTap);
}
}
}
private void scaleImage(float deltaScale, float focusX, float focusY, boolean stretchImageToSuper) {
float lowerScale, upperScale;
if (stretchImageToSuper) {
lowerScale = superMinScale;
upperScale = superMaxScale;
} else {
lowerScale = minScale;
upperScale = maxScale;
}
float origScale = normalizedScale;
normalizedScale *= deltaScale;
if (normalizedScale > upperScale) {
normalizedScale = upperScale;
deltaScale = upperScale / origScale;
} else if (normalizedScale < lowerScale) {
normalizedScale = lowerScale;
deltaScale = lowerScale / origScale;
}
matrix.postScale(deltaScale, deltaScale, focusX, focusY);
fixScaleTrans();
}
/**
* DoubleTapZoom calls a series of runnables which apply
* an animated zoom in/out graphic to the image.
* @author Ortiz
*
*/
private class DoubleTapZoom implements Runnable {
private final long startTime;
private static final float ZOOM_TIME = 500;
private final float startZoom, targetZoom;
private final float bitmapX, bitmapY;
private final boolean stretchImageToSuper;
private final AccelerateDecelerateInterpolator interpolator = new AccelerateDecelerateInterpolator();
private final PointF startTouch;
private final PointF endTouch;
DoubleTapZoom(float startZoom, float targetZoom, float focusX, float focusY, boolean stretchImageToSuper) {
setState(ANIMATE_ZOOM);
startTime = System.currentTimeMillis();
this.startZoom = startZoom;
this.targetZoom = targetZoom;
this.stretchImageToSuper = stretchImageToSuper;
PointF bitmapPoint = transformCoordTouchToBitmap(focusX, focusY, false);
this.bitmapX = bitmapPoint.x;
this.bitmapY = bitmapPoint.y;
//
// Used for translating image during scaling
//
startTouch = transformCoordBitmapToTouch(bitmapX, bitmapY);
endTouch = new PointF(viewWidth / 2, viewHeight / 2);
}
@Override
public void run() {
float t = interpolate();
float deltaScale = calculateDeltaScale(t);
scaleImage(deltaScale, bitmapX, bitmapY, stretchImageToSuper);
translateImageToCenterTouchPosition(t);
fixScaleTrans();
setImageMatrix(matrix);
if (t < 1f) {
//
// We haven't finished zooming
//
compatPostOnAnimation(this);
} else {
//
// Finished zooming
//
setState(NONE);
}
}
/**
* Interpolate between where the image should start and end in order to translate
* the image so that the point that is touched is what ends up centered at the end
* of the zoom.
* @param t
*/
private void translateImageToCenterTouchPosition(float t) {
float targetX = startTouch.x + t * (endTouch.x - startTouch.x);
float targetY = startTouch.y + t * (endTouch.y - startTouch.y);
PointF curr = transformCoordBitmapToTouch(bitmapX, bitmapY);
matrix.postTranslate(targetX - curr.x, targetY - curr.y);
}
/**
* Use interpolator to get t
* @return
*/
private float interpolate() {
long currTime = System.currentTimeMillis();
float elapsed = (currTime - startTime) / ZOOM_TIME;
elapsed = Math.min(1f, elapsed);
return interpolator.getInterpolation(elapsed);
}
/**
* Interpolate the current targeted zoom and get the delta
* from the current zoom.
* @param t
* @return
*/
private float calculateDeltaScale(float t) {
float zoom = startZoom + t * (targetZoom - startZoom);
return zoom / normalizedScale;
}
}
/**
* This function will transform the coordinates in the touch event to the coordinate
* system of the drawable that the imageview contain
* @param x x-coordinate of touch event
* @param y y-coordinate of touch event
* @param clipToBitmap Touch event may occur within view, but outside image content. True, to clip return value
* to the bounds of the bitmap size.
* @return Coordinates of the point touched, in the coordinate system of the original drawable.
*/
private PointF transformCoordTouchToBitmap(float x, float y, boolean clipToBitmap) {
matrix.getValues(m);
float origW = getDrawable().getIntrinsicWidth();
float origH = getDrawable().getIntrinsicHeight();
float transX = m[Matrix.MTRANS_X];
float transY = m[Matrix.MTRANS_Y];
float finalX = ((x - transX) * origW) / getImageWidth();
float finalY = ((y - transY) * origH) / getImageHeight();
if (clipToBitmap) {
finalX = Math.min(Math.max(x, 0), origW);
finalY = Math.min(Math.max(y, 0), origH);
}
return new PointF(finalX , finalY);
}
/**
* Inverse of transformCoordTouchToBitmap. This function will transform the coordinates in the
* drawable's coordinate system to the view's coordinate system.
* @param bx x-coordinate in original bitmap coordinate system
* @param by y-coordinate in original bitmap coordinate system
* @return Coordinates of the point in the view's coordinate system.
*/
private PointF transformCoordBitmapToTouch(float bx, float by) {
matrix.getValues(m);
float origW = getDrawable().getIntrinsicWidth();
float origH = getDrawable().getIntrinsicHeight();
float px = bx / origW;
float py = by / origH;
float finalX = m[Matrix.MTRANS_X] + getImageWidth() * px;
float finalY = m[Matrix.MTRANS_Y] + getImageHeight() * py;
return new PointF(finalX , finalY);
}
/**
* Fling launches sequential runnables which apply
* the fling graphic to the image. The values for the translation
* are interpolated by the Scroller.
* @author Ortiz
*
*/
private class Fling implements Runnable {
Scroller scroller;
int currX, currY;
Fling(int velocityX, int velocityY) {
setState(FLING);
scroller = new Scroller(context);
matrix.getValues(m);
int startX = (int) m[Matrix.MTRANS_X];
int startY = (int) m[Matrix.MTRANS_Y];
int minX, maxX, minY, maxY;
if (getImageWidth() > viewWidth) {
minX = viewWidth - (int) getImageWidth();
maxX = 0;
} else {
minX = maxX = startX;
}
if (getImageHeight() > viewHeight) {
minY = viewHeight - (int) getImageHeight();
maxY = 0;
} else {
minY = maxY = startY;
}
scroller.fling(startX, startY, velocityX, velocityY, minX,
maxX, minY, maxY);
currX = startX;
currY = startY;
}
public void cancelFling() {
if (scroller != null) {
setState(NONE);
scroller.forceFinished(true);
}
}
@Override
public void run() {
if (scroller.isFinished()) {
scroller = null;
return;
}
if (scroller.computeScrollOffset()) {
int newX = scroller.getCurrX();
int newY = scroller.getCurrY();
int transX = newX - currX;
int transY = newY - currY;
currX = newX;
currY = newY;
matrix.postTranslate(transX, transY);
fixTrans();
setImageMatrix(matrix);
compatPostOnAnimation(this);
}
}
}
@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
private void compatPostOnAnimation(Runnable runnable) {
if (VERSION.SDK_INT >= VERSION_CODES.JELLY_BEAN) {
postOnAnimation(runnable);
} else {
postDelayed(runnable, 1000/60);
}
}
private void printMatrixInfo() {
matrix.getValues(m);
Log.d(DEBUG, "Scale: " + m[Matrix.MSCALE_X] + " TransX: " + m[Matrix.MTRANS_X] + " TransY: " + m[Matrix.MTRANS_Y]);
}
}
