CODEWITHSUNDEEP
android
Ashwin Khadgi
Ashwin Khadgi

Reputation: 322

android Drag and Drop for TextView causing exception

I am trying to use inbuilt drag and drop functionality in android 4+. I have created my custom TextView for this purpose as 

public class DragSpotTextView extends TextView

The textview drag is working fine but when I drag the view on some dragspot(this is also textview) its giving exception as;

01-17 16:16:29.178: E/AndroidRuntime(1193): FATAL EXCEPTION: main
01-17 16:16:29.178: E/AndroidRuntime(1193): java.lang.ClassCastException: java.lang.String cannot be cast to android.text.Spannable
01-17 16:16:29.178: E/AndroidRuntime(1193):     at android.widget.TextView.onDragEvent(TextView.java:11223)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at android.view.View.dispatchDragEvent(View.java:13465)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1104)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1104)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1104)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1104)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1104)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1104)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at android.view.ViewRootImpl.handleDragEvent(ViewRootImpl.java:3471)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2620)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at android.os.Handler.dispatchMessage(Handler.java:99)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at android.os.Looper.loop(Looper.java:137)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at android.app.ActivityThread.main(ActivityThread.java:4424)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at java.lang.reflect.Method.invokeNative(Native Method)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at java.lang.reflect.Method.invoke(Method.java:511)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
01-17 16:16:29.178: E/AndroidRuntime(1193):     at dalvik.system.NativeStart.main(Native Method)

Upvotes: 5

Views: 1663

Answers (5)

Henrique
Henrique

Reputation: 5011

I had the same problem. I fixed it by creating a custom TextView and making sure I consumed the DragEvent.ACTION_DRAG_LOCATION event myself and let the parent class handle the other Drag events, like so:

public class CustomTextView extends TextView {

  @Override
  public boolean onDragEvent(DragEvent event) {
    if(event.getAction() == DragEvent.ACTION_DRAG_LOCATION) {
      return true;
    } else {
      return super.onDragEvent(event);
    }
  }

}

Hope it helps!

Upvotes: 1

Malcolm
Malcolm

Reputation: 41510

Here's another solution for those who need it. I had the same problem when I dragged the item to the TextView which handled drag events. Apparently, the line in the source which causes trouble is here in the TextView.onDragEvent() (3rd one in the following code):

 case DragEvent.ACTION_DRAG_LOCATION:
     final int offset = getOffsetForPosition(event.getX(), event.getY());
     Selection.setSelection((Spannable)mText, offset);
     return true;

The fix for me was to consume events of this type in my OnDragListener for this TextView:

 if (dragEvent.getAction() == DragEvent.ACTION_DRAG_LOCATION) return true;

This is a bug in Android, of course, this shouldn't normally happen.

Upvotes: 5

Daniel
Daniel

Reputation: 2878

For me the app crashed when my drag shadow, which was not a TextView, entered a drop zone that was a TextView.

My solution in this case was to wrap the drop TextView with a FrameLayout (I'm willing to bet that any *Layout would work) - not the most elegant solution performance-wise, but not the worst either :)

Upvotes: 0

argenkiwi
argenkiwi

Reputation: 2427

I had the same problem. I read this and then tried replacing the following line of code:

ClipData data = ClipData.newPlainText("myLabel", "myString");

with:

ClipData data = ClipData.newPlainText("myLabel", ((TextView) v).getText());

Apparently in the onDragEvent method, the second parameter is cast to Spannable, which throws an exception when using a String.

Upvotes: 0

Ashwin Khadgi
Ashwin Khadgi

Reputation: 322

Earlier I was using anonymous inline class for dragListener. Now I changed it and implement OnDragListener at class level. This way I solved it.

Upvotes: 0

Related Questions