onTouchListener for entire screen

Question

I have a screen filled with buttons, but want the onTouch-method to use the entire screen's coordinates. I first tried using a RelativeLayout with an onTouchListener, but never managed to make it "connect" with the listener (i.e. nothing happened when screen was touched), I also tried putting an ImageView on top of the screen, and then making this view invisible.

This last method gave correct responses to onClicks, but I never managed to make it invisible.

If this is the best solution, which I highly doubt, how do I make the ImageView totally invisible, without losing its onTouchListener (I've experimented with white backgroundColor and setAlpha(0)).

Can I somehow make the onTouchListener react to the whole screen, using global coordinates, while the screen is showing (and altering) several buttons (preferably without the invisible imageview)?

If you don't understand what I'm asking for, feel free to complain about that. I'll try to fill the gaps as needed.

Edit:

I've now managed to resolve the issue by using the regular onTouch-method. I ran into several problems making both ACTION_DOWN and ACTION_MOVE activate the buttons, but I finally got it working. For other people reading this: onInterceptTouchEvent could possibly be used (but I never figured out how to get the screen coordinates instead of the view-coordinates).

Solution 1

Sorry if I'm wrong, but I believe I've just had a similar problem. I wanted a title screen that displayed a picture and on the picture words that say "Click to go on" or something similar. I messed around for a bit and found that you can make a layout clickable.

    android:focusable="true" 
    android:id="@+id/titlescreenframe">

is in my xml file for my layout. The background image is simply in the background attribute (I realize you aren't using images)

Anyway, back in my activity

    private FrameLayout fl;
    ...
    fl = (FrameLayout)findViewById(R.id.titlescreenframe);
    fl.setOnClickListener(this);

And then I use a switch statement to handle that and the buttons that are on the next layout. Here if you need it: Using Switch Statement to Handle Button Clicks

Seems this should work with other layouts as well, and I don't have literally any views on my main layout. (unless the layout itself counts as one?)

Ha! Just realized you said you found the solution. Silly timing. I'll post on the off-chance this helps someone, happy coding everyone. :)

Solution 2

Have you tried onInterceptTouchEvent on the layout?

Solution 3

I used dispatchTouchEvent for a similar problem. You could consider it a drop-in replacement for onTouchEvent, except that it always sends you an event, even if it's over an existing view.

Return true if you're handling the event, otherwise, be sure to call super.dispatchTouchEvent() and return its result.

As for getting screen coordinates - simply call the MotionEvent's getRawX() and getRawY() rather than getX() and getY(). Those are the absolute screen coordinates, including the action bar and all. If you want to cross-reference those with views, getLocationOnScreen is probably the easiest solution.

Solution 4

touch event return's to child views first. and if you define onClick or onTouch listener for them, parnt view (for example fragment) will not receive any touch listener. So if you want define swipe listener for fragment in this situation, you must implement it in a new class:

    package com.neganet.QRelations.fragments;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.FrameLayout;

public class SwipeListenerFragment extends FrameLayout {
    private float x1,x2;
    static final int MIN_DISTANCE=150;
    private onSwipeEventDetected mSwipeDetectedListener;


    public SwipeListenerFragment(Context context) {
        super(context);
    }

    public SwipeListenerFragment(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public SwipeListenerFragment(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        boolean result=false;
        switch(ev.getAction())
        {
            case MotionEvent.ACTION_DOWN:
                x1 = ev.getX();
                break;
            case MotionEvent.ACTION_UP:
                x2 = ev.getX();
                float deltaX = x2 - x1;
                if (Math.abs(deltaX) > MIN_DISTANCE)
                {
                    if(deltaX<0)
                    {
                        result=true;
                        if(mSwipeDetectedListener!=null)
                            mSwipeDetectedListener.swipeLeftDetected();

                    }else if(deltaX>0){
                        result=true;
                        if(mSwipeDetectedListener!=null)
                            mSwipeDetectedListener.swipeRightDetected();
                    }
                }
                break;
        }
        return result;
    }

    public interface onSwipeEventDetected
    {
        public void swipeLeftDetected();
        public void swipeRightDetected();

    }

    public void registerToSwipeEvents(onSwipeEventDetected listener)
    {
        this.mSwipeDetectedListener=listener;
    }
}

you can make implements for other types of Layouts completely like this. this class can detect both right and left swipe and specially it returns onInterceptTouchEvent true after detect. its important because if we don't do it some times child views maybe receive event and both of Swipe for fragment and onClick for child view (for example) runs and cause some issues. after making this class, you must change your fragment xml file:

    <com.neganet.QRelations.fragments.SwipeListenerFragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:id="@+id/main_list_layout"
    android:clickable="true"
    android:focusable="true"
    android:focusableInTouchMode="true"
    android:layout_height="match_parent" tools:context="com.neganet.QRelations.fragments.mainList"
    android:background="@color/main_frag_back">

    <!-- TODO: Update blank fragment layout -->
    <android.support.v7.widget.RecyclerView
        android:id="@+id/farazList"
        android:scrollbars="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="left|center_vertical" />
</com.neganet.QRelations.fragments.SwipeListenerFragment>

you see that begin tag is the class that we made. now in fragment class:

            View view=inflater.inflate(R.layout.fragment_main_list, container, false);
        SwipeListenerFragment tdView=(SwipeListenerFragment) view;
        tdView.registerToSwipeEvents(this);


and then Implement SwipeListenerFragment.onSwipeEventDetected in it:

        @Override
    public void swipeLeftDetected() {
        Toast.makeText(getActivity(), "left", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void swipeRightDetected() {
        Toast.makeText(getActivity(), "right", Toast.LENGTH_SHORT).show();
    }

It's a little complicated but works perfect :)

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Comments

[keyser]

Dsouza I tried it, but wasn't satisfied. I've now managed to resolve the issue by using the regular onTouch-method. I ran into several problems making both ACTION_DOWN and ACTION_MOVE activate the buttons, but I finally got it working. For other people reading this: onInterceptTouchEvent could possibly be used (but I never figured out how to get the screen coordinates instead of the view-coordinates).

[Yenchi]

if your target is newer than 1.6, you can use android:onClick="functionname" directly instead of setting focusable and assign onclick listener in code.