/* * TouchImageView.java * By: Michael Ortiz * Updated By: Patrick Lackemacher * Updated By: Jonathan GERBAUD * ------------------- * Extends Android ImageView to include pinch zooming and panning. * Extends to support double tap */ package com.abewy.android.apps.klyph.widget; import com.squareup.picasso.PicassoDrawable; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Matrix; import android.graphics.PointF; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.Drawable; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.ScaleGestureDetector; import android.view.View; import android.widget.ImageView; public class TouchImageView extends ImageView { public interface TouchImageListener { public void onTouchImageScale(); } Matrix matrix = new Matrix(); // We can be in one of these 3 states static final int NONE = 0; static final int DRAG = 1; static final int ZOOM = 2; int mode = NONE; // Remember some things for zooming PointF last = new PointF(); PointF start = new PointF(); float minScale = 1f; float maxScale = 3f; float[] m; float redundantXSpace, redundantYSpace; float width, height; static final int CLICK = 3; float saveScale = 1f; float right, bottom, origWidth, origHeight, bmWidth, bmHeight; ScaleGestureDetector mScaleDetector; Context context; private TouchImageListener listener; public TouchImageView(Context context) { super(context); sharedConstructing(context); } public TouchImageView(Context context, AttributeSet attrs) { super(context, attrs); sharedConstructing(context); } private void sharedConstructing(Context context) { super.setClickable(true); this.context = context; mScaleDetector = new ScaleGestureDetector(context, new ScaleListener()); matrix.setTranslate(1f, 1f); m = new float[9]; setImageMatrix(matrix); setScaleType(ScaleType.MATRIX); setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { mScaleDetector.onTouchEvent(event); matrix.getValues(m); float x = m[Matrix.MTRANS_X]; float y = m[Matrix.MTRANS_Y]; PointF curr = new PointF(event.getX(), event.getY()); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: last.set(event.getX(), event.getY()); start.set(last); mode = DRAG; break; case MotionEvent.ACTION_MOVE: if (mode == DRAG) { float deltaX = curr.x - last.x; float deltaY = curr.y - last.y; float scaleWidth = Math.round(origWidth * saveScale); float scaleHeight = Math.round(origHeight * saveScale); if (scaleWidth < width) { deltaX = 0; if (y + deltaY > 0) deltaY = -y; else if (y + deltaY < -bottom) deltaY = -(y + bottom); } else if (scaleHeight < height) { deltaY = 0; if (x + deltaX > 0) deltaX = -x; else if (x + deltaX < -right) deltaX = -(x + right); } else { if (x + deltaX > 0) deltaX = -x; else if (x + deltaX < -right) deltaX = -(x + right); if (y + deltaY > 0) deltaY = -y; else if (y + deltaY < -bottom) deltaY = -(y + bottom); } matrix.postTranslate(deltaX, deltaY); last.set(curr.x, curr.y); } break; case MotionEvent.ACTION_UP: mode = NONE; int xDiff = (int) Math.abs(curr.x - start.x); int yDiff = (int) Math.abs(curr.y - start.y); if (xDiff < CLICK && yDiff < CLICK) performClick(); break; case MotionEvent.ACTION_POINTER_UP: mode = NONE; break; } setImageMatrix(matrix); invalidate(); return true; // indicate event was handled } }); } @Override public void setImageBitmap(Bitmap bm) { super.setImageBitmap(bm); if (bm != null) { bmWidth = bm.getWidth(); bmHeight = bm.getHeight(); } } @Override public void setImageDrawable(Drawable drawable) { super.setImageDrawable(drawable); if (drawable instanceof PicassoDrawable) { PicassoDrawable pDrawable = (PicassoDrawable) drawable; BitmapDrawable bitmapDrawable = (BitmapDrawable) pDrawable.getImage(); if (bitmapDrawable.getBitmap() != null) { bmWidth = bitmapDrawable.getBitmap().getWidth(); bmHeight = bitmapDrawable.getBitmap().getHeight(); } } } public void setMaxZoom(float x) { maxScale = x; } public void setOnScaleListener(TouchImageListener listener) { this.listener = listener; } private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener { @Override public boolean onScaleBegin(ScaleGestureDetector detector) { mode = ZOOM; if (listener != null) listener.onTouchImageScale(); return true; } @Override public boolean onScale(ScaleGestureDetector detector) { float mScaleFactor = detector.getScaleFactor(); float origScale = saveScale; saveScale *= mScaleFactor; if (saveScale > maxScale) { saveScale = maxScale; mScaleFactor = maxScale / origScale; } else if (saveScale < minScale) { saveScale = minScale; mScaleFactor = minScale / origScale; } right = width * saveScale - width - (2 * redundantXSpace * saveScale); bottom = height * saveScale - height - (2 * redundantYSpace * saveScale); if (origWidth * saveScale <= width || origHeight * saveScale <= height) { matrix.postScale(mScaleFactor, mScaleFactor, width / 2, height / 2); if (mScaleFactor < 1) { matrix.getValues(m); float x = m[Matrix.MTRANS_X]; float y = m[Matrix.MTRANS_Y]; if (mScaleFactor < 1) { if (Math.round(origWidth * saveScale) < width) { if (y < -bottom) matrix.postTranslate(0, -(y + bottom)); else if (y > 0) matrix.postTranslate(0, -y); } else { if (x < -right) matrix.postTranslate(-(x + right), 0); else if (x > 0) matrix.postTranslate(-x, 0); } } } } else { matrix.postScale(mScaleFactor, mScaleFactor, detector.getFocusX(), detector.getFocusY()); matrix.getValues(m); float x = m[Matrix.MTRANS_X]; float y = m[Matrix.MTRANS_Y]; if (mScaleFactor < 1) { if (x < -right) matrix.postTranslate(-(x + right), 0); else if (x > 0) matrix.postTranslate(-x, 0); if (y < -bottom) matrix.postTranslate(0, -(y + bottom)); else if (y > 0) matrix.postTranslate(0, -y); } } return true; } } public boolean canScrollHorizontally(int direction) { matrix.getValues(m); float x = Math.abs(m[Matrix.MTRANS_X]); float scaleWidth = Math.round(origWidth * saveScale); if (scaleWidth < width) { return false; } else { if (x - direction <= 0) return false; // reach left edge else if (x + width - direction >= scaleWidth) return false; // reach right edge return true; } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); width = MeasureSpec.getSize(widthMeasureSpec); height = MeasureSpec.getSize(heightMeasureSpec); // Fit to screen. float scale; float scaleX = width / bmWidth; float scaleY = height / bmHeight; scale = Math.min(scaleX, scaleY); matrix.setScale(scale, scale); setImageMatrix(matrix); saveScale = 1f; // Center the image redundantYSpace = height - (scale * bmHeight); redundantXSpace = width - (scale * bmWidth); redundantYSpace /= 2; redundantXSpace /= 2; matrix.postTranslate(redundantXSpace, redundantYSpace); origWidth = width - 2 * redundantXSpace; origHeight = height - 2 * redundantYSpace; right = width * saveScale - width - (2 * redundantXSpace * saveScale); bottom = height * saveScale - height - (2 * redundantYSpace * saveScale); setImageMatrix(matrix); } }