是否有支持水平和垂直平移/拖拉的視圖的可能性？最重要的是，我希望能夠縮放和雙擊縮放。 此視圖是否存在於Android上，或者有人知道某個項目是誰？水平和垂直平移/拖動和捏放縮放的視圖
爲了使它更加困難，需要將其他視圖（Button，TextView，VideoView等）添加到視圖中。當第一個/父視圖放大或移動時，子視圖（按鈕）需要隨父移動。
我已經嘗試了多種解決方案，但他們都沒有我正在尋找的選項。
我認爲這是可能實現你想要什麼，但有，據我所知建設解決方案吧。從你問題的第二部分我猜你不想要一個可縮放的View，而是一個ViewGroup這是所有視圖的超類，可以包含其他視圖（例如佈局）。下面是一些代碼，你可以從建立自己的ViewGroup大部分來自this博客文章開始：
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Rect;
import android.view.*;
public class ZoomableViewGroup extends ViewGroup {
private static final int INVALID_POINTER_ID = 1;
private int mActivePointerId = INVALID_POINTER_ID;
private float mScaleFactor = 1;
private ScaleGestureDetector mScaleDetector;
private Matrix mScaleMatrix = new Matrix();
private Matrix mScaleMatrixInverse = new Matrix();
private float mPosX;
private float mPosY;
private Matrix mTranslateMatrix = new Matrix();
private Matrix mTranslateMatrixInverse = new Matrix();
private float mLastTouchX;
private float mLastTouchY;
private float mFocusY;
private float mFocusX;
private float[] mInvalidateWorkingArray = new float[6];
private float[] mDispatchTouchEventWorkingArray = new float[2];
private float[] mOnTouchEventWorkingArray = new float[2];
public ZoomableViewGroup(Context context) {
super(context);
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
mTranslateMatrix.setTranslate(0, 0);
mScaleMatrix.setScale(1, 1);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
child.layout(l, t, l+child.getMeasuredWidth(), t + child.getMeasuredHeight());
}
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
measureChild(child, widthMeasureSpec, heightMeasureSpec);
}
}
}
@Override
protected void dispatchDraw(Canvas canvas) {
canvas.save();
canvas.translate(mPosX, mPosY);
canvas.scale(mScaleFactor, mScaleFactor, mFocusX, mFocusY);
super.dispatchDraw(canvas);
canvas.restore();
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
mDispatchTouchEventWorkingArray[0] = ev.getX();
mDispatchTouchEventWorkingArray[1] = ev.getY();
mDispatchTouchEventWorkingArray = screenPointsToScaledPoints(mDispatchTouchEventWorkingArray);
ev.setLocation(mDispatchTouchEventWorkingArray[0],
mDispatchTouchEventWorkingArray[1]);
return super.dispatchTouchEvent(ev);
}
/**
* Although the docs say that you shouldn't override this, I decided to do
* so because it offers me an easy way to change the invalidated area to my
* likening.
*/
@Override
public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
mInvalidateWorkingArray[0] = dirty.left;
mInvalidateWorkingArray[1] = dirty.top;
mInvalidateWorkingArray[2] = dirty.right;
mInvalidateWorkingArray[3] = dirty.bottom;
mInvalidateWorkingArray = scaledPointsToScreenPoints(mInvalidateWorkingArray);
dirty.set(Math.round(mInvalidateWorkingArray[0]), Math.round(mInvalidateWorkingArray[1]),
Math.round(mInvalidateWorkingArray[2]), Math.round(mInvalidateWorkingArray[3]));
location[0] *= mScaleFactor;
location[1] *= mScaleFactor;
return super.invalidateChildInParent(location, dirty);
}
private float[] scaledPointsToScreenPoints(float[] a) {
mScaleMatrix.mapPoints(a);
mTranslateMatrix.mapPoints(a);
return a;
}
private float[] screenPointsToScaledPoints(float[] a){
mTranslateMatrixInverse.mapPoints(a);
mScaleMatrixInverse.mapPoints(a);
return a;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
mOnTouchEventWorkingArray[0] = ev.getX();
mOnTouchEventWorkingArray[1] = ev.getY();
mOnTouchEventWorkingArray = scaledPointsToScreenPoints(mOnTouchEventWorkingArray);
ev.setLocation(mOnTouchEventWorkingArray[0], mOnTouchEventWorkingArray[1]);
mScaleDetector.onTouchEvent(ev);
final int action = ev.getAction();
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN: {
final float x = ev.getX();
final float y = ev.getY();
mLastTouchX = x;
mLastTouchY = y;
// Save the ID of this pointer
mActivePointerId = ev.getPointerId(0);
break;
}
case MotionEvent.ACTION_MOVE: {
// Find the index of the active pointer and fetch its position
final int pointerIndex = ev.findPointerIndex(mActivePointerId);
final float x = ev.getX(pointerIndex);
final float y = ev.getY(pointerIndex);
final float dx = x - mLastTouchX;
final float dy = y - mLastTouchY;
mPosX += dx;
mPosY += dy;
mTranslateMatrix.preTranslate(dx, dy);
mTranslateMatrix.invert(mTranslateMatrixInverse);
mLastTouchX = x;
mLastTouchY = y;
invalidate();
break;
}
case MotionEvent.ACTION_UP: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_CANCEL: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_POINTER_UP: {
// Extract the index of the pointer that left the touch sensor
final int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = ev.getPointerId(pointerIndex);
if (pointerId == mActivePointerId) {
// This was our active pointer going up. Choose a new
// active pointer and adjust accordingly.
final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
mLastTouchX = ev.getX(newPointerIndex);
mLastTouchY = ev.getY(newPointerIndex);
mActivePointerId = ev.getPointerId(newPointerIndex);
}
break;
}
}
return true;
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
if (detector.isInProgress()) {
mFocusX = detector.getFocusX();
mFocusY = detector.getFocusY();
}
mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 5.0f));
mScaleMatrix.setScale(mScaleFactor, mScaleFactor,
mFocusX, mFocusY);
mScaleMatrix.invert(mScaleMatrixInverse);
invalidate();
requestLayout();
return true;
}
}
}
這個類應該是能夠做到的，是圍繞拖動內容，並允許指縮放什麼，雙擊現在無法進行縮放，但在onTouchEvent方法中應該很容易實現。
如果您有任何疑問如何佈局的孩子的在你的ViewGroup中，我發現這個video非常有益的，或者如果你有任何問題，單一的方法是如何工作的或其他任何隨意問的意見。
這裏有一些錯誤，包括你需要擴展ViewGroup，你錯過了一些'}'。 – Marche101
@Artjom我想知道，爲什麼不在視圖組上使用setScaleX/Y，而不必從視頻剪輯，觸點等自己轉移？ –
當視圖達到1：1比例時是否可以停止縮小？實現起來很簡單嗎？ – edoardotognoni
此自定義視圖是Android標準的ImageView的子類，並增加了它（多）觸摸平移和縮放（和雙抽頭變焦，以及）：
https://github.com/sephiroth74/ImageViewZoom
http://blog.sephiroth.it/2011/04/04/imageview-zoom-and-scroll/
它類似於你已經知道的MikeOrtiz的TouchImageView，但增加了一些更多的功能。
您可以在視圖「堆棧」（Android FrameLayout或類似的東西）中使用它，以及其他需要的textView。 （我的意思是「一堆」視圖，就像一堆盤子或一堆牌一樣，換句話說，一堆視圖堆疊在Z軸上）
將所有視圖一起移動需要您可以控制Android手勢（多點觸控）機制並編寫所需的代碼。您的（非常複雜）需求沒有任何現成的解決方案。看看這篇文章：@Artjom答案固定，小錯誤
http://android-developers.blogspot.it/2010/06/making-sense-of-multitouch.html
轉播即牙套，進口，和擴展的ViewGroup。
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Rect;
import android.view.*;
public class ZoomableViewGroup extends ViewGroup {
private static final int INVALID_POINTER_ID = 1;
private int mActivePointerId = INVALID_POINTER_ID;
private float mScaleFactor = 1;
private ScaleGestureDetector mScaleDetector;
private Matrix mScaleMatrix = new Matrix();
private Matrix mScaleMatrixInverse = new Matrix();
private float mPosX;
private float mPosY;
private Matrix mTranslateMatrix = new Matrix();
private Matrix mTranslateMatrixInverse = new Matrix();
private float mLastTouchX;
private float mLastTouchY;
private float mFocusY;
private float mFocusX;
private float[] mInvalidateWorkingArray = new float[6];
private float[] mDispatchTouchEventWorkingArray = new float[2];
private float[] mOnTouchEventWorkingArray = new float[2];
public ZoomableViewGroup(Context context) {
super(context);
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
mTranslateMatrix.setTranslate(0, 0);
mScaleMatrix.setScale(1, 1);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
child.layout(l, t, l+child.getMeasuredWidth(), t + child.getMeasuredHeight());
}
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
measureChild(child, widthMeasureSpec, heightMeasureSpec);
}
}
}
@Override
protected void dispatchDraw(Canvas canvas) {
canvas.save();
canvas.translate(mPosX, mPosY);
canvas.scale(mScaleFactor, mScaleFactor, mFocusX, mFocusY);
super.dispatchDraw(canvas);
canvas.restore();
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
mDispatchTouchEventWorkingArray[0] = ev.getX();
mDispatchTouchEventWorkingArray[1] = ev.getY();
mDispatchTouchEventWorkingArray = screenPointsToScaledPoints(mDispatchTouchEventWorkingArray);
ev.setLocation(mDispatchTouchEventWorkingArray[0],
mDispatchTouchEventWorkingArray[1]);
return super.dispatchTouchEvent(ev);
}
/**
* Although the docs say that you shouldn't override this, I decided to do
* so because it offers me an easy way to change the invalidated area to my
* likening.
*/
@Override
public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
mInvalidateWorkingArray[0] = dirty.left;
mInvalidateWorkingArray[1] = dirty.top;
mInvalidateWorkingArray[2] = dirty.right;
mInvalidateWorkingArray[3] = dirty.bottom;
mInvalidateWorkingArray = scaledPointsToScreenPoints(mInvalidateWorkingArray);
dirty.set(Math.round(mInvalidateWorkingArray[0]), Math.round(mInvalidateWorkingArray[1]),
Math.round(mInvalidateWorkingArray[2]), Math.round(mInvalidateWorkingArray[3]));
location[0] *= mScaleFactor;
location[1] *= mScaleFactor;
return super.invalidateChildInParent(location, dirty);
}
private float[] scaledPointsToScreenPoints(float[] a) {
mScaleMatrix.mapPoints(a);
mTranslateMatrix.mapPoints(a);
return a;
}
private float[] screenPointsToScaledPoints(float[] a){
mTranslateMatrixInverse.mapPoints(a);
mScaleMatrixInverse.mapPoints(a);
return a;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
mOnTouchEventWorkingArray[0] = ev.getX();
mOnTouchEventWorkingArray[1] = ev.getY();
mOnTouchEventWorkingArray = scaledPointsToScreenPoints(mOnTouchEventWorkingArray);
ev.setLocation(mOnTouchEventWorkingArray[0], mOnTouchEventWorkingArray[1]);
mScaleDetector.onTouchEvent(ev);
final int action = ev.getAction();
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN: {
final float x = ev.getX();
final float y = ev.getY();
mLastTouchX = x;
mLastTouchY = y;
// Save the ID of this pointer
mActivePointerId = ev.getPointerId(0);
break;
}
case MotionEvent.ACTION_MOVE: {
// Find the index of the active pointer and fetch its position
final int pointerIndex = ev.findPointerIndex(mActivePointerId);
final float x = ev.getX(pointerIndex);
final float y = ev.getY(pointerIndex);
final float dx = x - mLastTouchX;
final float dy = y - mLastTouchY;
mPosX += dx;
mPosY += dy;
mTranslateMatrix.preTranslate(dx, dy);
mTranslateMatrix.invert(mTranslateMatrixInverse);
mLastTouchX = x;
mLastTouchY = y;
invalidate();
break;
}
case MotionEvent.ACTION_UP: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_CANCEL: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_POINTER_UP: {
// Extract the index of the pointer that left the touch sensor
final int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = ev.getPointerId(pointerIndex);
if (pointerId == mActivePointerId) {
// This was our active pointer going up. Choose a new
// active pointer and adjust accordingly.
final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
mLastTouchX = ev.getX(newPointerIndex);
mLastTouchY = ev.getY(newPointerIndex);
mActivePointerId = ev.getPointerId(newPointerIndex);
}
break;
}
}
return true;
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
if (detector.isInProgress()) {
mFocusX = detector.getFocusX();
mFocusY = detector.getFocusY();
}
mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 5.0f));
mScaleMatrix.setScale(mScaleFactor, mScaleFactor,
mFocusX, mFocusY);
mScaleMatrix.invert(mScaleMatrixInverse);
invalidate();
requestLayout();
return true;
}
}
}
完美的解決方案。禮炮。 –
我在ZoomableViewGroup中添加一個子視圖，在縮放後，孩子的觸摸座標出錯。我該如何解決它？ –
爲面向像我的問題誰：改變方法
'私人浮子[] screenPointsToScaledPoints的順序（浮動[]一個）'到：
'私人浮子[] screenPointsToScaledPoints（浮動[]一個）{ mScaleMatrixInverse。 mapPoints（一）; mTranslateMatrixInverse.mapPoints（a）; return a; }' –
基於給出的答案，我使用此代碼來獲得平移和縮放功能的工作。首先遇到支點問題。
public class ZoomableViewGroup extends ViewGroup {
// these matrices will be used to move and zoom image
private Matrix matrix = new Matrix();
private Matrix matrixInverse = new Matrix();
private Matrix savedMatrix = new Matrix();
// we can be in one of these 3 states
private static final int NONE = 0;
private static final int DRAG = 1;
private static final int ZOOM = 2;
private int mode = NONE;
// remember some things for zooming
private PointF start = new PointF();
private PointF mid = new PointF();
private float oldDist = 1f;
private float[] lastEvent = null;
private boolean initZoomApplied=false;
private float[] mDispatchTouchEventWorkingArray = new float[2];
private float[] mOnTouchEventWorkingArray = new float[2];
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
mDispatchTouchEventWorkingArray[0] = ev.getX();
mDispatchTouchEventWorkingArray[1] = ev.getY();
mDispatchTouchEventWorkingArray = screenPointsToScaledPoints(mDispatchTouchEventWorkingArray);
ev.setLocation(mDispatchTouchEventWorkingArray[0],
mDispatchTouchEventWorkingArray[1]);
return super.dispatchTouchEvent(ev);
}
private float[] scaledPointsToScreenPoints(float[] a) {
matrix.mapPoints(a);
return a;
}
private float[] screenPointsToScaledPoints(float[] a){
matrixInverse.mapPoints(a);
return a;
}
public ZoomableViewGroup(Context context) {
super(context);
init(context);
}
public ZoomableViewGroup(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public ZoomableViewGroup(Context context, AttributeSet attrs,
int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context);
}
/**
* Determine the space between the first two fingers
*/
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return (float)Math.sqrt(x * x + y * y);
}
/**
* Calculate the mid point of the first two fingers
*/
private void midPoint(PointF point, MotionEvent event) {
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x/2, y/2);
}
private void init(Context context){
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
child.layout(l, t, l+child.getMeasuredWidth(), t + child.getMeasuredHeight());
}
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
float[] values = new float[9];
matrix.getValues(values);
float container_width = values[Matrix.MSCALE_X]*widthSize;
float container_height = values[Matrix.MSCALE_Y]*heightSize;
//Log.d("zoomToFit", "m width: "+container_width+" m height: "+container_height);
//Log.d("zoomToFit", "m x: "+pan_x+" m y: "+pan_y);
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
measureChild(child, widthMeasureSpec, heightMeasureSpec);
if(i==0 && !initZoomApplied && child.getWidth()>0){
int c_w = child.getWidth();
int c_h = child.getHeight();
//zoomToFit(c_w, c_h, container_width, container_height);
}
}
}
}
private void zoomToFit(int c_w, int c_h, float container_width, float container_height){
float proportion_firstChild = (float)c_w/(float)c_h;
float proportion_container = container_width/container_height;
//Log.d("zoomToFit", "firstChildW: "+c_w+" firstChildH: "+c_h);
//Log.d("zoomToFit", "proportion-container: "+proportion_container);
//Log.d("zoomToFit", "proportion_firstChild: "+proportion_firstChild);
if(proportion_container<proportion_firstChild){
float initZoom = container_height/c_h;
//Log.d("zoomToFit", "adjust height with initZoom: "+initZoom);
matrix.postScale(initZoom, initZoom);
matrix.postTranslate(-1*(c_w*initZoom-container_width)/2, 0);
matrix.invert(matrixInverse);
}else {
float initZoom = container_width/c_w;
//Log.d("zoomToFit", "adjust width with initZoom: "+initZoom);
matrix.postScale(initZoom, initZoom);
matrix.postTranslate(0, -1*(c_h*initZoom-container_height)/2);
matrix.invert(matrixInverse);
}
initZoomApplied=true;
invalidate();
}
@Override
protected void dispatchDraw(Canvas canvas) {
canvas.save();
canvas.setMatrix(matrix);
super.dispatchDraw(canvas);
canvas.restore();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// handle touch events here
mOnTouchEventWorkingArray[0] = event.getX();
mOnTouchEventWorkingArray[1] = event.getY();
mOnTouchEventWorkingArray = scaledPointsToScreenPoints(mOnTouchEventWorkingArray);
event.setLocation(mOnTouchEventWorkingArray[0], mOnTouchEventWorkingArray[1]);
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
mode = DRAG;
lastEvent = null;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
}
lastEvent = new float[4];
lastEvent[0] = event.getX(0);
lastEvent[1] = event.getX(1);
lastEvent[2] = event.getY(0);
lastEvent[3] = event.getY(1);
//d = rotation(event);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
lastEvent = null;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
matrix.set(savedMatrix);
float dx = event.getX() - start.x;
float dy = event.getY() - start.y;
matrix.postTranslate(dx, dy);
matrix.invert(matrixInverse);
} else if (mode == ZOOM) {
float newDist = spacing(event);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = (newDist/oldDist);
matrix.postScale(scale, scale, mid.x, mid.y);
matrix.invert(matrixInverse);
}
}
break;
}
invalidate();
return true;
}
}
積分到onTouch功能，請訪問：http://judepereira.com/blog/multi-touch-in-android-translate-scale-and-rotate/ 感謝Artjom對他的做法dipatch觸摸事件。
我加了一個zoomToFit方法，這個方法在這一點上被評論，因爲大多數人不需要這個。它適合孩子的容器大小，並把第一個孩子作爲比例因子的參考。
如何限制比例因子？例如，我希望縮放比例在0.75和4之內。 – techtinkerer
你可以定義一個MAX_ZOOM：'int MAX_ZOOM = 4;'，然後在你發佈比例（matrix.postScale）之前添加這一行：'float [] values = new float [9]; matrix.getValues（values）;如果（比例*值[Matrix.MSCALE_X]> = MAX_ZOOM）{ \t scale = MAX_ZOOM/values [Matrix.MSCALE_X]; }' – Thomas
好代碼！縮放比較好（立即開始，這在Alex的代碼中並不是這樣）並且沒有樞軸點問題。但是，它不允許使用雙擊拖動操作進行縮放。 – Donkey
要獲得Alex的代碼添加放大以下更改
更好permormanceprivate class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
if (detector.isInProgress()) {
mFocusX = detector.getFocusX();
mFocusY = detector.getFocusY();
}
mFocusX = (mFocusX + mLastTouchX)/2; // get center of touch
mFocusY = (mFocusY + mLastTouchY)/2; // get center of touch
mScaleFactor = Math.max(1f, Math.min(mScaleFactor, 2.0f));
mScaleMatrix.setScale(mScaleFactor, mScaleFactor,mFocusX, mFocusY);
mScaleMatrix.invert(mScaleMatrixInverse);
invalidate();
requestLayout();
return true;
}
}
Thomas答案几乎是最好的（我有我的手機上的一個位置錯誤）：縮放立即開始（這是不是這樣的與Alex的代碼），並在右側的中心點進行縮放。
但是，與Alex的代碼相反，無法使用「雙擊 - 拖動」手勢進行縮放（不是衆所周知的手勢，而是非常有用的手勢，只能用一個手指進行縮放，就像Google Chrome或Google地圖應用）。因此，這裏是Thomas的代碼的修改，以使其能夠（和固定子視圖位置錯誤）：
public class ZoomableView extends ViewGroup {
// States.
private static final byte NONE = 0;
private static final byte DRAG = 1;
private static final byte ZOOM = 2;
private byte mode = NONE;
// Matrices used to move and zoom image.
private Matrix matrix = new Matrix();
private Matrix matrixInverse = new Matrix();
private Matrix savedMatrix = new Matrix();
// Parameters for zooming.
private PointF start = new PointF();
private PointF mid = new PointF();
private float oldDist = 1f;
private float[] lastEvent = null;
private long lastDownTime = 0l;
private float[] mDispatchTouchEventWorkingArray = new float[2];
private float[] mOnTouchEventWorkingArray = new float[2];
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
mDispatchTouchEventWorkingArray[0] = ev.getX();
mDispatchTouchEventWorkingArray[1] = ev.getY();
mDispatchTouchEventWorkingArray = screenPointsToScaledPoints(mDispatchTouchEventWorkingArray);
ev.setLocation(mDispatchTouchEventWorkingArray[0], mDispatchTouchEventWorkingArray[1]);
return super.dispatchTouchEvent(ev);
}
public ZoomableView(Context context) {
super(context);
init(context);
}
public ZoomableView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public ZoomableView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context);
}
private void init(Context context) {
}
/**
* Determine the space between the first two fingers
*/
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return (float) Math.sqrt(x * x + y * y);
}
/**
* Calculate the mid point of the first two fingers
*/
private void midPoint(PointF point, MotionEvent event) {
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x/2, y/2);
}
private float[] scaledPointsToScreenPoints(float[] a) {
matrix.mapPoints(a);
return a;
}
private float[] screenPointsToScaledPoints(float[] a) {
matrixInverse.mapPoints(a);
return a;
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
child.layout(left, top, left + child.getMeasuredWidth(), top + child.getMeasuredHeight());
}
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
measureChild(child, widthMeasureSpec, heightMeasureSpec);
}
}
}
@Override
protected void dispatchDraw(Canvas canvas) {
float[] values = new float[9];
matrix.getValues(values);
canvas.save();
canvas.translate(values[Matrix.MTRANS_X], values[Matrix.MTRANS_Y]);
canvas.scale(values[Matrix.MSCALE_X], values[Matrix.MSCALE_Y]);
super.dispatchDraw(canvas);
canvas.restore();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// handle touch events here
mOnTouchEventWorkingArray[0] = event.getX();
mOnTouchEventWorkingArray[1] = event.getY();
mOnTouchEventWorkingArray = scaledPointsToScreenPoints(mOnTouchEventWorkingArray);
event.setLocation(mOnTouchEventWorkingArray[0], mOnTouchEventWorkingArray[1]);
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
mode = DRAG;
lastEvent = null;
long downTime = event.getDownTime();
if (downTime - lastDownTime < 300l) {
float density = getResources().getDisplayMetrics().density;
if (Math.max(Math.abs(start.x - event.getX()), Math.abs(start.y - event.getY())) < 40.f * density) {
savedMatrix.set(matrix);
mid.set(event.getX(), event.getY());
mode = ZOOM;
lastEvent = new float[4];
lastEvent[0] = lastEvent[1] = event.getX();
lastEvent[2] = lastEvent[3] = event.getY();
}
lastDownTime = 0l;
} else {
lastDownTime = downTime;
}
start.set(event.getX(), event.getY());
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
}
lastEvent = new float[4];
lastEvent[0] = event.getX(0);
lastEvent[1] = event.getX(1);
lastEvent[2] = event.getY(0);
lastEvent[3] = event.getY(1);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
lastEvent = null;
break;
case MotionEvent.ACTION_MOVE:
final float density = getResources().getDisplayMetrics().density;
if (mode == DRAG) {
matrix.set(savedMatrix);
float dx = event.getX() - start.x;
float dy = event.getY() - start.y;
matrix.postTranslate(dx, dy);
matrix.invert(matrixInverse);
if (Math.max(Math.abs(start.x - event.getX()), Math.abs(start.y - event.getY())) > 20.f * density) {
lastDownTime = 0l;
}
} else if (mode == ZOOM) {
if (event.getPointerCount() > 1) {
float newDist = spacing(event);
if (newDist > 10f * density) {
matrix.set(savedMatrix);
float scale = (newDist/oldDist);
matrix.postScale(scale, scale, mid.x, mid.y);
matrix.invert(matrixInverse);
}
} else {
matrix.set(savedMatrix);
float scale = event.getY()/start.y;
matrix.postScale(scale, scale, mid.x, mid.y);
matrix.invert(matrixInverse);
}
}
break;
}
invalidate();
return true;
}
}
如何在'onTouchEvent'上獲得轉換後的x，y座標？ – isuru
我對Thomas的回答有問題。我的視圖的點擊框低於實際視圖的位置（對於android <25 API）。我想通過dispatchDraw方法解決問題。因爲我對矩陣一無所知，所以我非常失望。你dispatchDraw修復了這個問題。我真的想知道這個魔法是如何工作的。我想了解矩陣，也許還有使用Rect對象的ViewPort技術。你能建議好的資源來學習嗎？ 我真的不喜歡做點什麼，當我無法弄清楚它是如何工作的。 謝謝你的代碼，謝謝你@Thomas aswell。 – Kotsu
這是最好的解決方案。 – Chandru
對於那些誰感興趣的縮放/平移的LinearLayout，我修改了由Alex發佈的版本將事情垂直放置，並將平移視爲可見視圖。我使用這個來自PDFRenderer的位圖。我已經測試過這個，但是如果你發現任何錯誤，請發帖，因爲我也想知道它們！
注：我選擇不實施雙擊，因爲QuickScale的作品。
public class ZoomableLinearLayout extends ViewGroup {
private static final int INVALID_POINTER_ID = 1;
private int mActivePointerId = INVALID_POINTER_ID;
private float mScaleFactor = 1;
private ScaleGestureDetector mScaleDetector;
private Matrix mScaleMatrix = new Matrix();
private Matrix mScaleMatrixInverse = new Matrix();
private float mPosX;
private float mPosY;
private Matrix mTranslateMatrix = new Matrix();
private Matrix mTranslateMatrixInverse = new Matrix();
private float mLastTouchX;
private float mLastTouchY;
private float mFocusY;
private float mFocusX;
private int mCanvasWidth;
private int mCanvasHeight;
private float[] mInvalidateWorkingArray = new float[6];
private float[] mDispatchTouchEventWorkingArray = new float[2];
private float[] mOnTouchEventWorkingArray = new float[2];
private boolean mIsScaling;
public ZoomableLinearLayout(Context context) {
super(context);
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
mTranslateMatrix.setTranslate(0, 0);
mScaleMatrix.setScale(1, 1);
}
public ZoomableLinearLayout(Context context, AttributeSet attributeSet) {
super(context, attributeSet);
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
mTranslateMatrix.setTranslate(0, 0);
mScaleMatrix.setScale(1, 1);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
child.layout(l, t, l+child.getMeasuredWidth(), t += child.getMeasuredHeight());
}
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int height = 0;
int width = 0;
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
measureChild(child, widthMeasureSpec, heightMeasureSpec);
height += child.getMeasuredHeight();
width = Math.max(width, child.getMeasuredWidth());
}
}
mCanvasWidth = width;
mCanvasHeight = height;
}
@Override
protected void dispatchDraw(Canvas canvas) {
canvas.save();
canvas.translate(mPosX, mPosY);
canvas.scale(mScaleFactor, mScaleFactor, mFocusX, mFocusY);
super.dispatchDraw(canvas);
canvas.restore();
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
mDispatchTouchEventWorkingArray[0] = ev.getX();
mDispatchTouchEventWorkingArray[1] = ev.getY();
mDispatchTouchEventWorkingArray = screenPointsToScaledPoints(mDispatchTouchEventWorkingArray);
ev.setLocation(mDispatchTouchEventWorkingArray[0],
mDispatchTouchEventWorkingArray[1]);
return super.dispatchTouchEvent(ev);
}
/**
* Although the docs say that you shouldn't override this, I decided to do
* so because it offers me an easy way to change the invalidated area to my
* likening.
*/
@Override
public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
mInvalidateWorkingArray[0] = dirty.left;
mInvalidateWorkingArray[1] = dirty.top;
mInvalidateWorkingArray[2] = dirty.right;
mInvalidateWorkingArray[3] = dirty.bottom;
mInvalidateWorkingArray = scaledPointsToScreenPoints(mInvalidateWorkingArray);
dirty.set(Math.round(mInvalidateWorkingArray[0]), Math.round(mInvalidateWorkingArray[1]),
Math.round(mInvalidateWorkingArray[2]), Math.round(mInvalidateWorkingArray[3]));
location[0] *= mScaleFactor;
location[1] *= mScaleFactor;
return super.invalidateChildInParent(location, dirty);
}
private float[] scaledPointsToScreenPoints(float[] a) {
mScaleMatrix.mapPoints(a);
mTranslateMatrix.mapPoints(a);
return a;
}
private float[] screenPointsToScaledPoints(float[] a){
mTranslateMatrixInverse.mapPoints(a);
mScaleMatrixInverse.mapPoints(a);
return a;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
mOnTouchEventWorkingArray[0] = ev.getX();
mOnTouchEventWorkingArray[1] = ev.getY();
mOnTouchEventWorkingArray = scaledPointsToScreenPoints(mOnTouchEventWorkingArray);
ev.setLocation(mOnTouchEventWorkingArray[0], mOnTouchEventWorkingArray[1]);
mScaleDetector.onTouchEvent(ev);
final int action = ev.getAction();
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN: {
final float x = ev.getX();
final float y = ev.getY();
mLastTouchX = x;
mLastTouchY = y;
// Save the ID of this pointer
mActivePointerId = ev.getPointerId(0);
break;
}
case MotionEvent.ACTION_MOVE: {
// Find the index of the active pointer and fetch its position
final int pointerIndex = ev.findPointerIndex(mActivePointerId);
final float x = ev.getX(pointerIndex);
final float y = ev.getY(pointerIndex);
if (mIsScaling && ev.getPointerCount() == 1) {
// Don't move during a QuickScale.
mLastTouchX = x;
mLastTouchY = y;
break;
}
float dx = x - mLastTouchX;
float dy = y - mLastTouchY;
float[] topLeft = {0f, 0f};
float[] bottomRight = {getWidth(), getHeight()};
/*
* Corners of the view in screen coordinates, so dx/dy should not be allowed to
* push these beyond the canvas bounds.
*/
float[] scaledTopLeft = screenPointsToScaledPoints(topLeft);
float[] scaledBottomRight = screenPointsToScaledPoints(bottomRight);
dx = Math.min(Math.max(dx, scaledBottomRight[0] - mCanvasWidth), scaledTopLeft[0]);
dy = Math.min(Math.max(dy, scaledBottomRight[1] - mCanvasHeight), scaledTopLeft[1]);
mPosX += dx;
mPosY += dy;
mTranslateMatrix.preTranslate(dx, dy);
mTranslateMatrix.invert(mTranslateMatrixInverse);
mLastTouchX = x;
mLastTouchY = y;
invalidate();
break;
}
case MotionEvent.ACTION_UP: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_CANCEL: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_POINTER_UP: {
// Extract the index of the pointer that left the touch sensor
final int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = ev.getPointerId(pointerIndex);
if (pointerId == mActivePointerId) {
// This was our active pointer going up. Choose a new
// active pointer and adjust accordingly.
final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
mLastTouchX = ev.getX(newPointerIndex);
mLastTouchY = ev.getY(newPointerIndex);
mActivePointerId = ev.getPointerId(newPointerIndex);
}
break;
}
}
return true;
}
private float getMaxScale() {
return 2f;
}
private float getMinScale() {
return 1f;
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
mIsScaling = true;
mFocusX = detector.getFocusX();
mFocusY = detector.getFocusY();
float[] foci = {mFocusX, mFocusY};
float[] scaledFoci = screenPointsToScaledPoints(foci);
mFocusX = scaledFoci[0];
mFocusY = scaledFoci[1];
return true;
}
@Override
public void onScaleEnd(ScaleGestureDetector detector) {
mIsScaling = false;
}
@Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
mScaleFactor = Math.max(getMinScale(), Math.min(mScaleFactor, getMaxScale()));
mScaleMatrix.setScale(mScaleFactor, mScaleFactor, mFocusX, mFocusY);
mScaleMatrix.invert(mScaleMatrixInverse);
invalidate();
return true;
}
}
}
我使用的是這裏發佈的代碼的一些修改版本。此ZoomLayout使用Android手勢識別器進行滾動和縮放。在縮放或平移時，它還保留了數據透視和邊界。
爲了保持鍋的界限：
if (contentSize != null)
{
float[] values = new float[9];
matrix.getValues(values);
float totX = values[Matrix.MTRANS_X] + distanceX;
float totY = values[Matrix.MTRANS_Y] + distanceY;
float sx = values[Matrix.MSCALE_X];
Rect viewableRect = new Rect();
ZoomLayout.this.getDrawingRect(viewableRect);
float offscreenWidth = contentSize.width() - (viewableRect.right - viewableRect.left);
float offscreenHeight = contentSize.height() - (viewableRect.bottom - viewableRect.top);
float maxDx = (contentSize.width() - (contentSize.width()/sx)) * sx;
float maxDy = (contentSize.height() - (contentSize.height()/sx)) * sx;
if (totX > 0 && distanceX > 0)
{
distanceX = 0;
}
if (totY > 0 && distanceY > 0)
{
distanceY = 0;
}
if(totX*-1 > offscreenWidth+maxDx && distanceX < 0)
{
distanceX = 0;
}
if(totY*-1 > offscreenHeight+maxDy && distanceY < 0)
{
distanceY = 0;
}
}
嗨，你得到這個問題的最終解決方案？你能分享一下嗎？ –
如果你可以分享你的解決方案，這將是很好的... – pawpaw