How to webview swipe gesture detect with multitouch zooming enabled withing a flipper

问题

So is there a way for a webview control to detect a swipe while capable of doing multitouch zoom and having build-in zoom controls?

回答1:

YES!There is a way of doing that by implementing WebView and creating a custom Webview This way the custom WebView has build in swipe detection having at the same time multi touch and build in controls for zoom.

//Declaring the custom Webview and put into a viewflipper


MyWebView[] webview =new MyWebView[2];
    flipper = (ViewFlipper) findViewById(R.id.ViewFlipper);

 webview[i] = new MyWebView(this);
 webview[i].setWebViewClient(new HelloWebViewClient());
 webview[i].getSettings().setJavaScriptEnabled(false);
 webview[i].setInitialScale(60); 
 webview[i].getSettings().setBuiltInZoomControls(true);

    flipper.addView(webview[0]);
    flipper.addView(webview[1]);

and here is the custom webview

 public class MyWebView extends WebView {
  public MyWebView(Context context) {
   super(context);
  }



@Override 
     public boolean onTouchEvent(MotionEvent evt) {   

         boolean consumed = super.onTouchEvent(evt); 
     if (isClickable()) { 
         switch (evt.getAction()) { 
     case MotionEvent.ACTION_DOWN: 
         lastTouchX = evt.getX(); 
         lastTouchY = evt.getY();
         downXValue = evt.getX();
         downTime = evt.getEventTime();
         hasMoved = false; 
         break; 
     case MotionEvent.ACTION_MOVE: 
         hasMoved = moved(evt); 
         break; 
     case MotionEvent.ACTION_UP: 
        float currentX = evt.getX();
           long currentTime = evt.getEventTime();
           float difference = Math.abs(downXValue - currentX);
           long time = currentTime - downTime;

           Log.i("Touch Event:",  "Distance: " + difference + "px Time: " + time + "ms");

           if ( (downXValue < currentX) && (time < 220) && (difference > 100) ) {
               go_back();
           }



             if ( (downXValue > currentX) && (time < 220) && (difference > 100) ) {
                   go_forward();


                  }

                 //if (!moved(evt)) performClick(); 
                 break; 
             } 
         } 
         return consumed || isClickable(); 
     } 
  float downXValue;
  long downTime;
     private float lastTouchX, lastTouchY; 
     private boolean hasMoved = false; 
     private boolean moved(MotionEvent evt) { 
         return hasMoved || 
             Math.abs(evt.getX() - lastTouchX) > 10.0 || 
             Math.abs(evt.getY() - lastTouchY) > 10.0; 
     }

 }

And that's It.You have Build in swipe detection.Code is in a bit "pseudocode" and haven't cleaned it up but Overriding the onTouchEvent in MotionEvent.ACTION_MOVE and case MotionEvent.ACTION_UP should do the trick.You can also play with the time and difference bounds .

来源：https://stackoverflow.com/questions/3245165/how-to-webview-swipe-gesture-detect-with-multitouch-zooming-enabled-withing-a-fl