Android TextView text selection

Question

Is there an API to set the start and end selection (index) in textview so that it can call CustomSelectionActionMode?

According to documentation, the Selection class has a SetSelection function that takes 3 arguments: spannable, start and end. But how do I retrieve the Selection class from TextView class?

score 0 · Answer 1 · answered Nov 16 '18 at 00:56

Here is the answer,

https://stackoverflow.com/a/22833303/1177865

mTextView.setCustomSelectionActionModeCallback(new Callback() {

    @Override
    public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
        // Remove the "select all" option
        menu.removeItem(android.R.id.selectAll);
        // Remove the "cut" option
        menu.removeItem(android.R.id.cut);
        // Remove the "copy all" option
        menu.removeItem(android.R.id.copy);
        return true;
    }

    @Override
    public boolean onCreateActionMode(ActionMode mode, Menu menu) {
        // Called when action mode is first created. The menu supplied
        // will be used to generate action buttons for the action mode

        // Here is an example MenuItem
        menu.add(0, DEFINITION, 0, "Definition").setIcon(R.drawable.ic_action_book);
        return true;
    }

    @Override
    public void onDestroyActionMode(ActionMode mode) {
        // Called when an action mode is about to be exited and
        // destroyed
    }

    @Override
    public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
        switch (item.getItemId()) {
            case DEFINITION:
                int min = 0;
                int max = mTextView.getText().length();
                if (mTextView.isFocused()) {
                    final int selStart = mTextView.getSelectionStart();
                    final int selEnd = mTextView.getSelectionEnd();

                    min = Math.max(0, Math.min(selStart, selEnd));
                    max = Math.max(0, Math.max(selStart, selEnd));
                }
                // Perform your definition lookup with the selected text
                final CharSequence selectedText = mTextView.getText().subSequence(min, max);
                // Finish and close the ActionMode
                mode.finish();
                return true;
            default:
                break;
        }
        return false;
    }

});

I have added setCustomSelectionActionModeCallback. This part of the code is working initially until I added Touch listener. Apparently, with touch listener, long press no longer select the text. Hence, my question is how I can manually set the SelectionStart and SelectionEnd so that it will trigger CustomSelectionActionModeCallback. — Tek Mun, Nov 16 '18 at 01:37
you override the touch listener and the control cannot flow as usual. Can you post your ontouch listener? I think the idea is to continue to pass the control to parent by using return false. https://developer.android.com/reference/android/view/View.OnTouchListener. Sample code https://stackoverflow.com/questions/11690504/how-to-use-view-ontouchlistener-instead-of-onclick — hjchin, Nov 16 '18 at 05:50

score 0 · Answer 2 · answered Nov 16 '18 at 07:22

bool LongPress()
{
    if (longpressed == 1)
    {
    int x = (int)downX;
    int y = (int)downY;
    x -= textview.PaddingLeft;
    y -= textview.PaddingTop;
    x += textview.ScrollX;
    y += textview.ScrollY;
    Android.Text.Layout layout = textview.Layout;
    int line = layout.GetLineForVertical(y);
    int off = layout.GetOffsetForHorizontal(line, x);
    var clickspans = ss.GetSpans(off, off, Java.Lang.Class.FromType(typeof(ClickableSpan)));
    if (clickspans.Count() > 0)
    {
        ClickableSpan clickspan = (ClickableSpan)clickspans[0];
        startselection = ss.GetSpanStart(clickspan);
        endselection = ss.GetSpanEnd(clickspan);
        /*
        This is where I intend to add Selection.SetSelection(ss, startselection, endselection);
        */
        //textview.StartActionMode(textview.CustomSelectionActionModeCallback, ActionModeType.Floating);
    }
    longpressed = 2;
    }
    return false;
}

private void TouchLabel(object sender, TouchEventArgs e)
{
    MotionEvent motionevt = e.Event;
    if (MotionEvent.ActionToString(motionevt.Action) == "ACTION_DOWN")
    {
    Device.StartTimer(TimeSpan.FromMilliseconds(500), LongPress);
    longpressed = 1;
    }
    else if (MotionEvent.ActionToString(motionevt.Action) == "ACTION_MOVE")
    {
    longpressed = 2;
    }
    else if ((MotionEvent.ActionToString(motionevt.Action) == "ACTION_UP") || (MotionEvent.ActionToString(motionevt.Action) == "ACTION_CANCEL"))
    {
    if (longpressed == 1)
    {
        longpressed = 2;
    }
    longpressed = 0;
    }
}

This is written in C# for Xamarin.Android. I am using timer to detect "LongPress" and would like to set the "selected/highlighted" inside the LongPress function.

Android TextView text selection

2 Answers2