Detect swipe using onTouchListener in ScrollView

Question

I'm using the following code to detect swipe in my Activity:

getWindow().getDecorView().getRootView().setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                int action = event.getAction();
                if(action == MotionEvent.ACTION_DOWN){

                    downX = event.getX();
                    downY = event.getY();
                    //mSwipeDetected = Action.None;
                    return true; // allow other events like Click to be processed
                }
                else if(action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL){
                     upX = event.getX();
                     upY = event.getY();

                     float deltaX = downX - upX;
                     float deltaY = downY - upY;

                    // horizontal swipe detection
                    if (Math.abs(deltaX) > MIN_DISTANCE) {
                        // left or right
                        if (deltaX < 0) {
                            Log.i(TAG, "Swipe Left to Right");
                            //mSwipeDetected = Action.LR;
                            onClickPrevQues(getWindow().getDecorView().getRootView());

                            return false;
                        }
                        if (deltaX > 0) {
                            Log.i(TAG, "Swipe Right to Left");
                            onClickNextQues(getWindow().getDecorView().getRootView());
                           // mSwipeDetected = Action.RL;
                            return false;
                        }
                    } else if (Math.abs(deltaY) > MIN_DISTANCE) { // vertical swipe
                                                                    // detection
                        // top or down
                        if (deltaY < 0) {
                            Log.i(TAG, "Swipe Top to Bottom");
                            //mSwipeDetected = Action.TB;
                            return false;
                        }
                        if (deltaY > 0) {
                            Log.i(TAG, "Swipe Bottom to Top");
                            //mSwipeDetected = Action.BT;
                            return false;
                        }
                    }
                    return false;
                }
                else if(action == MotionEvent.ACTION_MOVE){
                    return true;
                }
                return false;
            }
        });

The code is working fine in case of LinearLayout. Surprisingly the same is not working in case if I wrap the Linearlayout inside ScrollView. What is the problem here?

Edit:
Layout:

    <?xml version="1.0" encoding="utf-8"?>
<ScrollView
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">
<RelativeLayout 
    android:id="@+id/RelativeLayout1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="#ffffff"
    android:gravity="center_horizontal" >

    <RelativeLayout
        android:id="@+id/RelativeLayout2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:orientation="horizontal"
        android:paddingBottom="0dp"
        android:paddingLeft="620dip"
        android:paddingTop="15dip" >

        <TextView
            android:id="@+id/text_unattempted"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:paddingTop="2dp"
            android:text="TextView"
            android:textColor="#b4cacc"
            android:textStyle="bold" />
    </RelativeLayout>

    <LinearLayout
        android:id="@+id/LinearLayout1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/RelativeLayout2"
        android:gravity="center_horizontal"
        android:orientation="horizontal"
        android:paddingBottom="5dip"
        android:paddingTop="5dip" >

        <RelativeLayout
            android:id="@+id/relative_group"
            android:layout_width="fill_parent"
            android:layout_height="260dp"
            android:layout_marginLeft="20dp"
            android:orientation="vertical" >

            <TextView
                android:id="@+id/txt_question_nu"
                android:layout_width="180dp"
                android:layout_height="wrap_content"
                android:layout_alignParentLeft="true"
                android:layout_alignParentTop="true"
                android:paddingTop="0dp"
                android:text="Question 1"
                android:textColor="#b4cacc"
                android:textSize="28dp"
                android:textStyle="bold" />

            <TextView
                android:id="@+id/question"
                android:layout_width="fill_parent"
                android:layout_height="400dp"
                android:layout_alignLeft="@+id/txt_question_nu"
                android:layout_below="@+id/txt_question_nu"
                android:layout_marginBottom="20dp"
                android:layout_marginTop="24dp"
                android:textColor="#000000"
                android:textSize="20dp" />

            <WebView
                android:id="@+id/questionimage"
                android:layout_width="wrap_content"
                android:layout_height="400dp"
                android:layout_alignLeft="@+id/txt_question_nu"
                android:layout_alignParentBottom="true"
                android:layout_below="@+id/txt_question_nu"
                android:layout_marginTop="24dp"
                android:fadeScrollbars="false"
                android:textColor="#000000"
                android:textSize="20dp"
                android:textStyle="bold" />

            <Button
                android:id="@+id/hintSolBtn"
                style="@style/HomeButton"
                android:layout_width="40dp"
                android:layout_height="30dp"
                android:layout_alignParentTop="true"
                android:layout_toRightOf="@+id/txt_question_nu"
                android:background="#90b7bb"
                android:onClick="onClickHintSol"
                android:scaleType="centerInside"
                android:text="Hint"
                android:textColor="#ffffff" />
        </RelativeLayout>
    </LinearLayout>

    <RelativeLayout
        android:id="@+id/LinearLayout2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_marginTop="15dp"
        android:layout_below="@+id/radio_question_group"
        android:layout_alignParentLeft="true"
        android:orientation="horizontal"
        android:paddingTop="5dip" >

        <ImageButton
            android:id="@+id/abandonButton"
            style="@style/HomeButton"
            android:layout_width="wrap_content"
            android:layout_height="50dp"
            android:layout_alignParentRight="true"
            android:layout_marginRight="45dp"
            android:onClick="onAbandonAssess"
            android:paddingLeft="6dp"
            android:scaleType="centerInside"
            android:src="@drawable/abandon"
            android:visibility="gone" />

        <Button
            android:id="@+id/submitBtn"
            android:layout_width="150dp"
            android:layout_height="50dp"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:layout_marginRight="63dp"
            android:background="#00b6c6"
            android:onClick="onSubmitAssess"
            android:paddingLeft="6dp"
            android:scaleType="centerInside"
            android:text="Submit"
            android:textColor="#ffffff"
            android:textSize="22dp" />

        <ImageButton
            android:id="@+id/prevBtn"
            style="@style/HomeButton"
            android:layout_width="120dp"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_weight="0.01"
            android:onClick="onClickPrevQues"
            android:scaleType="centerInside"
            android:src="@drawable/previous" />

        <ImageButton
            android:id="@+id/nextBtn"
            style="@style/HomeButton"
            android:layout_width="120dp"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:layout_toRightOf="@+id/prevBtn"
            android:onClick="onClickNextQues"
            android:scaleType="centerInside"
            android:src="@drawable/next" />
    </RelativeLayout>

    <TextView
        android:id="@+id/answer_choices"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/LinearLayout1"
        android:layout_marginLeft="37dp"
        android:text="Answer Choices"
        android:textColor="#b4cacc"
        android:textSize="20dp"
        android:textStyle="bold" />

    <RadioGroup
        android:id="@+id/radio_question_group"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/answer_choices"
        android:layout_below="@+id/answer_choices" >

        <RadioButton
            android:id="@+id/answer1"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:button="@drawable/radiostate"
            android:checked="false"
            android:layout_marginTop="10dp"
            android:hapticFeedbackEnabled="true"
            android:height="100dp"
            android:textColor="#000000" />

        <RadioButton
            android:id="@+id/answer2"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:button="@drawable/radiostate"
            android:layout_marginTop="10dp"
            android:checked="false"
            android:hapticFeedbackEnabled="true"
            android:textColor="#000000" />

        <RadioButton
            android:id="@+id/answer3"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:button="@drawable/radiostate"
            android:layout_marginTop="10dp"
            android:checked="false"
            android:hapticFeedbackEnabled="true"
            android:textColor="#000000" />

        <RadioButton
            android:id="@+id/answer4"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:button="@drawable/radiostate"
            android:layout_marginTop="10dp"
            android:checked="false"
            android:hapticFeedbackEnabled="true"
            android:textColor="#000000" />
    </RadioGroup>

    <!-- <ImageView
        android:id="@+id/pen_and_paper_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:src="@drawable/pen_paper"
        android:visibility="gone" /> -->

    <ImageButton
        android:id="@+id/erase"
        android:layout_width="35dp"
        android:layout_height="35dp"
        android:layout_above="@+id/radio_question_group"
        android:layout_below="@+id/LinearLayout1"
        android:layout_toRightOf="@+id/answer_choices"
        android:onClick="onEraseChoice"
        android:src="@drawable/eraser"
        android:visibility="visible" />

</RelativeLayout>
</ScrollView>

Vituperate

ScrollView taking the touch event and not the linear layout...better use listview insted – Assume

@Assume I've a bunch of stuffs inside the LinearLayout, that cannot fit together in the ListView. ScrollView is the only way – Vituperate

can u post the screen shot of linearLayout – Assume

@Assume edited question to add layout – Vituperate

Answer 1

I think this is what you are looking for:

Swipe event in android ScrollView

Darill

link you provided is down – Alfrediaalfredo

It can be reached from archive.org. This is the link: web.archive.org/web/20190922193715/http://… – Missus

Answer 2

You must set OntouchListener to ScrollView.

ScrollView scrollView = (ScrollView) findViewById(R.id.scrollView1);
scrollView.setOnTouchListener(new View.OnTouchListener() {
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        switch(event.getAction()) {
            case MotionEvent.ACTION_DOWN: {
                downX = event.getX();
                break;
            }
            
            case MotionEvent.ACTION_UP: {
                upX = event.getX();

                float deltaX = downX - upX;

                if (Math.abs(deltaX) > 0) {
                    if (deltaX >= 0) {
                        swipeToRight();
                        return true;
                    } else {
                        swipeToLeft();
                        return true;
                    }
                }
                break;
            }
        }

        return false;
    }
});

Photochromy

this is the right answer...but you forgot to initialize the downX and upX variables before the onTouch event – Rosalie

... and for a better usability I suggest to add a condition to the value of deltaX before swiping...something like if(Math.abs(deltaX)>0 && Math.abs(deltaX)>150) – Rosalie

Answer 3

mSlop = ViewConfiguration.get(getActivity()).getScaledTouchSlop();
boolean mIsSwiping = false;

public boolean onTouch(View v, MotionEvent event) {
    //Timber.d("onTouch, v.getId %d, event.getActionMasked %d", v.getId(), event.getActionMasked());
    switch (event.getActionMasked()) {
        case MotionEvent.ACTION_DOWN:
            mDownX = event.getX();
            mDownY = event.getY();
            break;
        case MotionEvent.ACTION_UP:
        case MotionEvent.ACTION_CANCEL:
            mIsSwiping = false;
            break;
        case MotionEvent.ACTION_MOVE:
            float deltaX = event.getX() - mDownX;
            float deltaY = event.getY() - mDownY;
            if (!mIsSwiping && Math.abs(deltaX) > mSlop && Math.abs(deltaY) < mSlop) {
                mIsSwiping = true;
                if (deltaX > 0) {
                    Timber.d("swipe from left to right, slop %d", mSlop);
                    // TODO:
                } else {
                    Timber.d("swipe from right to left");
                    // TODO:
                }
                return true;
            } else if (!mIsSwiping && Math.abs(deltaY) > mSlop) {
                mIsSwiping = true;
                Timber.d("swipe vertical");
                return true;
            }

    }
    return false;
}

Tactless

You should consider adding some explanatin to your answer. even with some code, this is pretty vague. – Needlewoman