Android UI How to - Dispatch event to a control








The following code shows how to Dispatch event to a control.

Example

Layout activity_main.xml file


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/text_touch"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:gravity="center"
        android:text="Scroll Anywhere Here" />

    <HorizontalScrollView
        android:id="@+id/scroll_view"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:background="#CCC">
        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:orientation="horizontal" >
            <ImageView
                android:layout_width="250dp"
                android:layout_height="match_parent"
                android:scaleType="fitXY"
                android:src="@drawable/ic_launcher" />
            <ImageView
                android:layout_width="250dp"
                android:layout_height="match_parent"
                android:scaleType="fitXY"
                android:src="@drawable/ic_launcher" />
            <ImageView
                android:layout_width="250dp"
                android:layout_height="match_parent"
                android:scaleType="fitXY"
                android:src="@drawable/ic_launcher" />
            <ImageView
                android:layout_width="250dp"
                android:layout_height="match_parent"
                android:scaleType="fitXY"
                android:src="@drawable/ic_launcher" />
        </LinearLayout>
    </HorizontalScrollView>
</LinearLayout>

Main activity Java code

package com.java2s.myapplication3.app;
//  ww w . j  av a2  s.  c om
import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.widget.HorizontalScrollView;
import android.widget.TextView;

public class MainActivity extends Activity implements View.OnTouchListener {

    private TextView mTouchText;
    private HorizontalScrollView mScrollView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mTouchText = (TextView) findViewById(R.id.text_touch);
        mScrollView = (HorizontalScrollView) findViewById(R.id.scroll_view);
        mTouchText.setOnTouchListener(this);
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        event.setLocation(event.getX(), mScrollView.getHeight() / 2);
        mScrollView.dispatchTouchEvent(event);
        return true;
    }
}
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