我遇到了问题：我不知道如何让layout缩放。我找到了一些技巧来解决ImageView，Bitmap或Drawable或类似问题，但不适用于layout。我想放一个自定义视图数组（实际上只是一个矩形，我重写onDraw）。有没有办法解决这个问题（我只是不想重新发明轮子）或者我需要自己做所有事情？也许有些人做过这样的事情？我尝试用ScaleGestureDetector做一些事情，但失败了。我的代码如下所示
public class Seat extends View {
private float mLastTouchX;
private float mLastTouchY;
private float mPosX;
private float mPosY;
private float mWidth;
private float mHeight;
private static final int INVALID_POINTER_ID = -1;
public static final int ACTION_POINTER_INDEX_MASK = 0xff00;
public static final int ACTION_POINTER_INDEX_SHIFT = 8;
// The ‘active pointer’ is the one currently moving our object.
private int mActivePointerId = INVALID_POINTER_ID;
private ScaleGestureDetector mScaleDetector;
private float mScaleFactor = 1.f;
private boolean checked = false;
private boolean reserved = false;
private Place place;
public Seat(PlacesActivity context, Place place) {
super(context);
setOnClickListener(new OnSeatClickListener(context));
if (place.getReservation() != 1 || place.getStatus() != 1) {
reserved = true;
}
this.place = place;
this.mPosX = place.getX();
this.mPosY = place.getY();
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams((int) mWidth, (int) mHeight);
params.leftMargin = (int) mPosX;
params.topMargin = (int) mPosY;
setLayoutParams(params);
RelativeLayout parent = (RelativeLayout) getParent();
Place place = (Place) getTag();
for (int i = 0; i < parent.getChildCount(); i++) {
Seat seat = (Seat) parent.getChildAt(i);
Place placeToCompare = (Place) seat.getTag();
if (place.getId() == placeToCompare.getId()) {
parent.removeViewAt(i);
parent.addView(this, i, params);
}
}
if (reserved)
canvas.drawColor(Color.GRAY);
else if (checked)
canvas.drawColor(Color.RED);
else
canvas.drawColor(Color.GREEN);
}
public void setChecked() {
checked = true;
}
public void setUnchecked() {
checked = false;
}
public boolean isChecked() {
return checked;
}
public void setReserved() {
reserved = true;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
// Let the ScaleGestureDetector inspect all events.
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;
mActivePointerId = ev.getPointerId(0);
break;
}
case MotionEvent.ACTION_MOVE: {
final int pointerIndex = ev.findPointerIndex(mActivePointerId);
final float x = ev.getX(pointerIndex);
final float y = ev.getY(pointerIndex);
// Only move if the ScaleGestureDetector isn't processing a gesture.
if (!mScaleDetector.isInProgress()) {
final float dx = x - mLastTouchX;
final float dy = y - mLastTouchY;
mPosX += dx;
mPosY += dy;
mWidth *= mScaleFactor;
mHeight *= mScaleFactor;
invalidate();
}
mLastTouchX = x;
mLastTouchY = y;
break;
}
case MotionEvent.ACTION_UP: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_CANCEL: {
mActivePointerId = INVALID_POINTER_ID;
break;
}
case MotionEvent.ACTION_POINTER_UP: {
final int pointerIndex = (ev.getAction() & ACTION_POINTER_INDEX_MASK)
>> 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 OnSeatClickListener implements OnClickListener {
private PlacesActivity context;
public OnSeatClickListener(PlacesActivity context) {
this.context = context;
}
@Override
public void onClick(View view) {
if (!reserved) {
Seat seat = (Seat) view;
seat.checked = !seat.checked;
view.invalidate();
Place place = (Place) view.getTag();
context.changeSeatState(place);
Toast toast = Toast.makeText(context, "Place " + place.getPlace() + " row " + place.getRow(), Toast.LENGTH_SHORT);
toast.setGravity(Gravity.CENTER, 0, 0);
toast.show();
}
}
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
// Don't let the object get too small or too large.
mScaleFactor = Math.max(0.5f, Math.min(mScaleFactor, 2.0f));
invalidate();
return true;
}
}
}
这是一类视图，我想要缩放的布局包含一些这样的视图。我尝试申请ScaleGestureDetector，但也失败了。
答案 0 :(得分：0)
我已经制作了自定义布局...并且它的缩放正确...我也实现了滚动但不是那么好......我正在努力...在这里我为你分享我的代码。它会帮助你很多，如果你比我更好滚动....那么让我知道......
这里是
public class ZoomLayout extends RelativeLayout implements OnDoubleTapListener, OnGestureListener{
//ScalingFactor i.e. Amount of Zoom
static float mScaleFactor = 1.0f;
// Maximum and Minimum Zoom
private static float MIN_ZOOM = 1.0f;
private static float MAX_ZOOM = 2.0f;
//Different Operation to be used
private final int NONE_OPERATION=0;
private final int DRAG_OPERATION=1;
private final int ZOOM_OPERATION=2;
private float mWidth= 1280;
private float mHeight=800;
// Mode to select the operation
private int mode;
//Track X and Y coordinate of the finger when it first touches the screen
private float mInitialX = 0f;
private float mInitialY = 0f;
// Track the Bound of the Image after zoom to calculate the offset
static Rect mClipBound;
// mDetector to detect the scaleGesture for the pinch Zoom
private ScaleGestureDetector mDetector;
// mDoubleTapDetector to detect the double tap
private GestureDetector mDoubleTapDetector;
//Pivot point for Scaling
static float gx=0,gy=0;
boolean mdrag=false,mZoom=false;
public ZoomLayout(Context context, AttributeSet attrs) {
super(context, attrs);
setWillNotDraw(false);
mClipBound = new Rect();
// Intialize ScaleGestureDetector
mDetector = new ScaleGestureDetector(getContext(), new ZoomListener());
mDoubleTapDetector = new GestureDetector(context,this);
mDoubleTapDetector.setOnDoubleTapListener(this);
}
public ZoomLayout(Context context) {
super(context);
setWillNotDraw(false);
mClipBound = new Rect();
// Intialize ScaleGestureDetector
mDetector = new ScaleGestureDetector(getContext(), new ZoomListener());
mDoubleTapDetector = new GestureDetector(context,this);
mDoubleTapDetector.setOnDoubleTapListener(this);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// Handles all type of motion-events possible
switch(event.getAction() ) {
case MotionEvent.ACTION_DOWN:
// Event occurs when the first finger is pressed on the Screen
Log.d("ZoomPrint", "Event: Action_Down " );
mInitialX = event.getX();
mInitialY = event.getY();
break;
case MotionEvent.ACTION_POINTER_DOWN:
//Event occurs when the second finger is pressed down
Log.d("ZoomPrint", "Event: Action_Pointer_Down " );
// If second finger is pressed on the screen with the first set the Mode to Zoom operation
mode=ZOOM_OPERATION;
break;
case MotionEvent.ACTION_POINTER_UP:
Log.d("ZoomPrint", "Event: Action_Pointer_UP " );
mdrag=true;
case MotionEvent.ACTION_UP:
//Event occurs when all the finger are taken of the screen
Log.d("ZoomPrint", "Event: Action_UP " );
//If all the fingers are taken up there will be no operation
mode = NONE_OPERATION;
mdrag=false;
break;
}
// give the event to the mDetector to get the scaling Factor
mDetector.onTouchEvent(event);
// give the event to the mDoubleTapDetector for the doubleTap
mDoubleTapDetector.onTouchEvent(event);
if(!mdrag)
invalidate();
return true;
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
onTouchEvent(ev);
return super.onInterceptTouchEvent(ev);
// return true;
}
@Override
public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
return super.invalidateChildInParent(location, dirty);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b)
{
int count = getChildCount();
for(int i=0;i<count;i++){
View child = getChildAt(i);
if(child.getVisibility()!=GONE){
RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams)child.getLayoutParams();
child.layout(
(int)(params.leftMargin ),
(int)(params.topMargin ),
(int)((params.leftMargin + child.getMeasuredWidth()) ),
(int)((params.topMargin + child.getMeasuredHeight()))
);
}
}
}
@Override
protected void dispatchDraw(Canvas canvas) {
//Save the canvas to set the scaling factor returned from detector
canvas.save(Canvas.MATRIX_SAVE_FLAG);
canvas.scale(mScaleFactor, mScaleFactor,gx,gy);
super.dispatchDraw(canvas);
mClipBound = canvas.getClipBounds();
canvas.restore();
}
private class ZoomListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
// getting the scaleFactor from the detector
mScaleFactor *= detector.getScaleFactor(); // gives the scaling factor from the previous scaling to the current
// Log.d("ZoomPrint", "detector scaling Factor" + mScaleFactor);
gx = detector.getFocusX();
gy = detector.getFocusY();
// Limit the scale factor in the MIN and MAX bound
mScaleFactor= Math.max(Math.min(mScaleFactor, MAX_ZOOM),MIN_ZOOM);
// Log.d("ZoomPrint", "Bounded scaling Factor" + mScaleFactor);
/*//Force canvas to redraw itself only if the one event is to happen (say Zooming only ) else do not invalidate here for multi operations
As what we de for scrolling or panning will not reflect here. So we will add this in onDraw method
invalidate();*/
// Here we are only zooming so invalidate has to be done
// invalidate();
// requestLayout();
// we have handle the onScale
return true;
}
}
@Override
public boolean onDoubleTap(MotionEvent e) {
// Make the mScaleFactor to its normal value
if(mScaleFactor>1.0f)
{
mScaleFactor=1.0f;
}
// Force the canvas to redraw itself again as the changes has been occured.
invalidate();
requestLayout();
return false;
}
@Override
public boolean onDoubleTapEvent(MotionEvent e) {
// Log.d("ZoomPrint", "OnDoubleTapEvent");
return false;
}
@Override
public boolean onSingleTapConfirmed(MotionEvent e) {
// Log.d("ZoomPrint", "OnSingleTap");
return false;
}
@Override
public boolean onDown(MotionEvent e) {
// TODO Auto-generated method stub
return false;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2,
float velocityX, float velocityY) {
return false;
}
@Override
public void onLongPress(MotionEvent e) {
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
int distX= (int) distanceX, distY =(int) distanceY;
//Log.d("Print"," X " + this.mClipBound.left +" Y " + this.mClipBound.right + " b "+ this.mClipBound.bottom + " g" + this.mClipBound.top) ;
Log.d("Print", "Scroll X " + distanceX + " Y " + distanceY);
if(this.mClipBound.left<=0)
this.scrollTo(-280, 0);
else if(this.mClipBound.top<=0)
this.scrollTo(0, -250);
else if (this.mClipBound.right>=1047)
this.scrollTo(280, 0);
else if (this.mClipBound.bottom>=800)
this.scrollTo(0, 250);
else
this.scrollBy((int)distanceX,(int)distanceY);
return true;
}
@Override
public void onShowPress(MotionEvent e) {
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
return false;
}