Android intercept paste\copy\cut on editText

Question

How can I intercept this kind of events ?

I need to add some logic when the user trying to paste some text into my EditText i know i can use TextWatcher but this entrypoint not good for me becuase i only need to intercept in case of paste and not every time the user press my EditText,

Answer 1

Seems there isn't much you can do by using the API: android paste event

Source reading to the rescue!

I dug into the Android Source of the TextView (EditText is a TextView with some different configuration) and found out that the menu used to offer the cut/copy/paste options is just a modified ContextMenu (source).

As for a normal context-menu, the View must create the menu (source) and then handle the interaction in a callback-method (source).

Because the handling method is public, we can simply hook into it by extending EditText and overwriting the method to react on the different actions. Here is an example-implementation:

import android.content.Context;
import android.util.AttributeSet;
import android.widget.EditText;
import android.widget.Toast;

/**
 * An EditText, which notifies when something was cut/copied/pasted inside it.
 * @author Lukas Knuth
 * @version 1.0
 */
public class MonitoringEditText extends EditText {

    private final Context context;

    /*
        Just the constructors to create a new EditText...
     */
    public MonitoringEditText(Context context) {
        super(context);
        this.context = context;
    }

    public MonitoringEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.context = context;
    }

    public MonitoringEditText(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        this.context = context;
    }

    /**
     * <p>This is where the "magic" happens.</p>
     * <p>The menu used to cut/copy/paste is a normal ContextMenu, which allows us to
     *  overwrite the consuming method and react on the different events.</p>
     * @see <a href="http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/2.3_r1/android/widget/TextView.java#TextView.onTextContextMenuItem%28int%29">Original Implementation</a>
     */
    @Override
    public boolean onTextContextMenuItem(int id) {
        // Do your thing:
        boolean consumed = super.onTextContextMenuItem(id);
        // React:
        switch (id){
            case android.R.id.cut:
                onTextCut();
                break;
            case android.R.id.paste:
                onTextPaste();
                break;
            case android.R.id.copy:
                onTextCopy();
        }
        return consumed;
    }

    /**
     * Text was cut from this EditText.
     */
    public void onTextCut(){
        Toast.makeText(context, "Cut!", Toast.LENGTH_SHORT).show();
    }

    /**
     * Text was copied from this EditText.
     */
    public void onTextCopy(){
        Toast.makeText(context, "Copy!", Toast.LENGTH_SHORT).show();
    }

    /**
     * Text was pasted into the EditText.
     */
    public void onTextPaste(){
        Toast.makeText(context, "Paste!", Toast.LENGTH_SHORT).show();
    }
}

Now, when the user uses cut/copy/paste, a Toast is shown (of course you could do other things, too).

The neat thing is that this works down to Android 1.5 and you don't need to re-create the context-menu (like suggested in the above linked question), which will keep the constant look of the platform (for example with HTC Sense).

Answer 2

There is a much simpler way, although not 100% reliable.

Add TextChangedListener to your editbox:

EditText et = (EditText) mView.findViewById(R.id.yourEditText);
et.addTextChangedListener(new TextWatcher() {

  @Override
  public void onTextChanged(CharSequence s, int start, int before, int count) {
     if (count > 2) toast("text was pasted");
  }

  @Override
  public void beforeTextChanged(CharSequence s, int start, int count, int after) {

  }

  public void afterTextChanged(Editable s) {
               
  }
});

If the text changes for more than 2 characters, you can assume it was pasted (some smileys take up two characters).

Of course it will not detect pasting when the user pastes 1 or 2 characters, and it will falsely report pasting if the change in text was triggered by something else.

But for most purposes, it gets the job done 👍