[英]Implements Double Tap on Image
我有一個活動,僅添加了1張圖像,並添加了平移/縮放/旋轉系統。 我需要在圖像上實現雙擊以向代碼中添加另一個功能,但我無法做到這一點。我嘗試通過onClick方法將setOnClickListener添加到圖像中,盡管沒有任何代碼錯誤,但是什么也沒有發生。
public class LastActivity extends AppCompatActivity
{
ImageView my_View;
float scalediff;
private static final int NONE = 0;
private static final int DRAG = 1;
private static final int ZOOM = 2;
private int mode = NONE;
private float oldDist = 1f;
private float d = 0f;
private float newRot = 0f;
@SuppressLint("ClickableViewAccessibility")
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_last);
my_View = findViewById(R.id.my_View);
final Bundle mBundle = getIntent().getExtras();
if (mBundle != null)
{
my_View.setImageResource(mBundle.getInt("fullImg"));
}
init();
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int sWidth = size.x;
int sHeight = size.y;
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(800, 800);
my_View.setLayoutParams(layoutParams);
my_View.setOnTouchListener(new View.OnTouchListener() {
RelativeLayout.LayoutParams parms;
int startwidth;
int startheight;
float dx = 0, dy = 0, x = 0, y = 0;
float angle = 0;
@Override
public boolean onTouch(View v, MotionEvent event) {
final ImageView view = (ImageView) v;
((BitmapDrawable) view.getDrawable()).setAntiAlias(true);
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
parms = (RelativeLayout.LayoutParams) view.getLayoutParams();
startwidth = parms.width;
startheight = parms.height;
dx = event.getRawX() - parms.leftMargin;
dy = event.getRawY() - parms.topMargin;
mode = DRAG;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
mode = ZOOM;
}
d = rotation(event);
break;
case MotionEvent.ACTION_UP:
break;
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
x = event.getRawX();
y = event.getRawY();
parms.leftMargin = (int) (x - dx);
parms.topMargin = (int) (y - dy);
parms.rightMargin = 0;
parms.bottomMargin = 0;
parms.rightMargin = parms.leftMargin + (5 * parms.width);
parms.bottomMargin = parms.topMargin + (10 * parms.height);
view.setLayoutParams(parms);
} else if (mode == ZOOM) {
if (event.getPointerCount() == 2) {
newRot = rotation(event);
angle = newRot - d;
x = event.getRawX();
y = event.getRawY();
float newDist = spacing(event);
if (newDist > 10f) {
float scale = newDist / oldDist * view.getScaleX();
if (scale > 0.6) {
scalediff = scale;
view.setScaleX(scale);
view.setScaleY(scale);
}
}
view.animate().rotationBy(angle).setDuration(0).setInterpolator(new LinearInterpolator()).start();
x = event.getRawX();
y = event.getRawY();
parms.leftMargin = (int) ((x - dx) + scalediff);
parms.topMargin = (int) ((y - dy) + scalediff);
parms.rightMargin = 0;
parms.bottomMargin = 0;
parms.rightMargin = parms.leftMargin + (5 * parms.width);
parms.bottomMargin = parms.topMargin + (10 * parms.height);
view.setLayoutParams(parms);
}
}
break;
}
return true;
}
});
}
private void init()
{
my_View = findViewById(R.id.my_View);
}
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);
}
private float rotation(MotionEvent event)
{
double delta_x = (event.getX(0) - event.getX(1));
double delta_y = (event.getY(0) - event.getY(1));
double radians = Math.atan2(delta_y, delta_x);
return (float) Math.toDegrees(radians);
}
}
如何在不破壞原始代碼的情況下實現對圖像的雙擊?
這是onClick方法
int c = 0;
my_View.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View view)
{
c++;
Handler handler = new Handler();
Runnable run = new Runnable()
{
@Override
public void run()
{
c = 0;
}
};
handler.postDelayed(run,350);
if (c == 2)
{
// event code
}
}
});
您可以實現適應此答案的手勢檢測器:
GestureDetector gestureDetector = new GestureDetector(context, new GestureListener());
}
// skipping measure calculation and drawing
// delegate the event to the gesture detector
@Override
public boolean onTouchEvent(MotionEvent e) {
return gestureDetector.onTouchEvent(e);
}
//since you already have the previous bookean for your original code to work, try changing "return true" (of your on touch event) to "return gestureDetector.onTouchEvent(e)"
private class GestureListener extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onDown(MotionEvent e) {
return true;
}
// event when double tap occurs
@Override
public boolean onDoubleTap(MotionEvent e) {
float x = e.getX();
float y = e.getY();
//double tapped
return true;
}
}
如果您在ggeasture檢測器方面遇到問題,並且原始觸摸偵聽器沒有反應,則只需在geaturelistener中獲取所有其他事件(將代碼復制到適當的事件中(tou將需要添加到onDown和onDoubleClicked中即可)您可能需要將“擴展簡單的手勢監聽器”更改為擴展手勢監聽器)
對我來說,更好,更有效的解決方案是將此帖子的鳥人答案添加到我的代碼中。
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