How to handle child view click event

[lushan1314]

I have a child's point of view, this is a picture, it's big. I'll give it a set the click event. But then the sliding event doesn't work. I want to do is to click on the image processing click event, sliding images to slide the whole card, Do you have what method? Thank you very much.

[Ludomancer]

Any progress on this issue? I am trying to do something similar.

Currently I am trying to pass the Touch event through even if a child is blocking the container but, below code fails to trigger OnTouchListener.onTouch under FlingCardListener;

package com.***.***;

import android.content.Context;
import android.support.v4.view.MotionEventCompat;
import android.support.v7.widget.CardView;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

/**
 * Created by erdin on 012, July, 12, 07, 2015.
 */
public class SwipeCardView extends CardView {
    public SwipeCardView(Context context)
    {
        super(context);
    }

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

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

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev)
    {
        onTouchEvent(ev);
        return false;
    }
}

[Ludomancer]

I have solved the issue by download and editing some classes in repository.

On SwipeFlingAdapterView; added following method

    public void addOnTouchListenersRecursive(ViewGroup vg)
    {
        vg.setOnTouchListener(flingCardListener);
        for(int i=0; i< vg.getChildCount(); ++i) {
            View nextChild = vg.getChildAt(i);
            if(nextChild instanceof ViewGroup) addOnTouchListenersRecursive((ViewGroup)nextChild);
            else nextChild.setOnTouchListener(flingCardListener);
        }
    } 

and replaced last line of setTopView method with

addOnTouchListenersRecursive((ViewGroup) mActiveCard);

I have also modified the FlingCardListener class to have a treshold before starting the actual dragging. You can find it below.

package com.lorentzos.flingswipe;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.graphics.PointF;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.OvershootInterpolator;

/**
 * Created by dionysis_lorentzos on 5/8/14
 * for package com.lorentzos.swipecards
 * and project Swipe cards.
 * Use with caution dinausaurs might appear!
 */

public class FlingCardListener implements View.OnTouchListener {

    private static final String TAG = FlingCardListener.class.getSimpleName();
    private static final int INVALID_POINTER_ID = -1;

    private final float objectX;
    private final float objectY;
    private final int objectH;
    private final int objectW;
    private final int parentWidth;
    private final FlingListener mFlingListener;
    private final Object dataObject;
    private final float halfWidth;
    private float BASE_ROTATION_DEGREES;

    private float aPosX;
    private float aPosY;
    private float aDownTouchX;
    private float aDownTouchY;

    // The active pointer is the one currently moving our object.
    private int mActivePointerId = INVALID_POINTER_ID;
    private View frame = null;

    private final int TOUCH_ABOVE = 0;
    private final int TOUCH_BELOW = 1;
    private int touchPosition;
    private final Object obj = new Object();
    private boolean isAnimationRunning = false;
    private boolean isDragging = false;
    private float MAX_COS = (float) Math.cos(Math.toRadians(45));

    public FlingCardListener(View frame, Object itemAtPosition, FlingListener flingListener) {
        this(frame, itemAtPosition, 15f, flingListener);
    }

    public FlingCardListener(View frame, Object itemAtPosition, float rotation_degrees, FlingListener flingListener) {
        super();
        this.frame = frame;
        this.objectX = frame.getX();
        this.objectY = frame.getY();
        this.objectH = frame.getHeight();
        this.objectW = frame.getWidth();
        this.halfWidth = objectW / 2f;
        this.dataObject = itemAtPosition;
        this.parentWidth = ((ViewGroup) frame.getParent()).getWidth();
        this.BASE_ROTATION_DEGREES = rotation_degrees;
        this.mFlingListener = flingListener;

    }

    public boolean onTouch(View view, MotionEvent event) {

        switch (event.getAction() & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_DOWN:

                // from http://android-developers.blogspot.com/2010/06/making-sense-of-multitouch.html
                // Save the ID of this pointer

                mActivePointerId = event.getPointerId(0);
                float x = 0;
                float y = 0;
                boolean success = false;
                try {
                    x = event.getX(mActivePointerId);
                    y = event.getY(mActivePointerId);
                    success = true;
                } catch (IllegalArgumentException e) {
                    Log.w(TAG, "Exception in onTouch(view, event) : " + mActivePointerId, e);
                }
                if (success) {
                    // Remember where we started
                    aDownTouchX = x;
                    aDownTouchY = y;
                    //to prevent an initial jump of the magnifier, aposX and aPosY must
                    //have the values from the magnifier frame
                    if (aPosX == 0) {
                        aPosX = frame.getX();
                    }
                    if (aPosY == 0) {
                        aPosY = frame.getY();
                    }

                    if (y < objectH / 2) {
                        touchPosition = TOUCH_ABOVE;
                    } else {
                        touchPosition = TOUCH_BELOW;
                    }
                }

                view.getParent().requestDisallowInterceptTouchEvent(true);
                break;

            case MotionEvent.ACTION_UP:
                mActivePointerId = INVALID_POINTER_ID;
                resetCardViewOnStack();
                view.getParent().requestDisallowInterceptTouchEvent(false);
                isDragging = false;
                break;

            case MotionEvent.ACTION_POINTER_DOWN:
                break;

            case MotionEvent.ACTION_POINTER_UP:
                // Extract the index of the pointer that left the touch sensor
                final int pointerIndex = (event.getAction() &
                        MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
                final int pointerId = event.getPointerId(pointerIndex);
                if (pointerId == mActivePointerId) {
                    // This was our active pointer going up. Choose a new
                    // active pointer and adjust accordingly.
                    final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
                    mActivePointerId = event.getPointerId(newPointerIndex);
                }
                isDragging = false;
                break;
            case MotionEvent.ACTION_MOVE:

                // Find the index of the active pointer and fetch its position
                final int pointerIndexMove = event.findPointerIndex(mActivePointerId);
                final float xMove = event.getX(pointerIndexMove);
                final float yMove = event.getY(pointerIndexMove);

                //from http://android-developers.blogspot.com/2010/06/making-sense-of-multitouch.html
                // Calculate the distance moved
                final float dx = xMove - aDownTouchX;
                final float dy = yMove - aDownTouchY;

                if(Math.abs(dx) > objectW * 0.1f || Math.abs(dy) > objectH * 0.1f || isDragging)
                {
                    Log.d(TAG, "Scrolling: " + dx + ":" + dy);

                    isDragging = true;

                    // Move the frame
                    aPosX += dx;
                    aPosY += dy;

                    // calculate the rotation degrees
                    float distobjectX = aPosX - objectX;
                    float rotation = BASE_ROTATION_DEGREES * 2.f * distobjectX / parentWidth;
                    if (touchPosition == TOUCH_BELOW)
                    {
                        rotation = -rotation;
                    }

                    //in this area would be code for doing something with the view as the frame moves.
                    frame.setX(aPosX);
                    frame.setY(aPosY);
                    frame.setRotation(rotation);
                    mFlingListener.onScroll(getScrollProgressPercent());
                }
                else Log.d(TAG, "Ignored: " + dx + ":" + dy);
                break;

            case MotionEvent.ACTION_CANCEL: {
                mActivePointerId = INVALID_POINTER_ID;
                view.getParent().requestDisallowInterceptTouchEvent(false);
                isDragging = false;
                break;
            }
        }

        return false;
    }

    private float getScrollProgressPercent() {
        if (movedBeyondLeftBorder()) {
            return -1f;
        } else if (movedBeyondRightBorder()) {
            return 1f;
        } else {
            float zeroToOneValue = (aPosX + halfWidth - leftBorder()) / (rightBorder() - leftBorder());
            return zeroToOneValue * 2f - 1f;
        }
    }

    private boolean resetCardViewOnStack() {
        if (movedBeyondLeftBorder()) {
            // Left Swipe
            onSelected(true, getExitPoint(-objectW), 100);
            mFlingListener.onScroll(-1.0f);
        } else if (movedBeyondRightBorder()) {
            // Right Swipe
            onSelected(false, getExitPoint(parentWidth), 100);
            mFlingListener.onScroll(1.0f);
        } else {
            float abslMoveDistance = Math.abs(aPosX - objectX);
            aPosX = 0;
            aPosY = 0;
            aDownTouchX = 0;
            aDownTouchY = 0;
            frame.animate()
                    .setDuration(200)
                    .setInterpolator(new OvershootInterpolator(1.5f))
                    .x(objectX)
                    .y(objectY)
                    .rotation(0);
            mFlingListener.onScroll(0.0f);
            if (abslMoveDistance < 4.0) {
                mFlingListener.onClick(dataObject);
            }
        }
        return false;
    }

    private boolean movedBeyondLeftBorder() {
        return aPosX + halfWidth < leftBorder();
    }

    private boolean movedBeyondRightBorder() {
        return aPosX + halfWidth > rightBorder();
    }

    public float leftBorder() {
        return parentWidth / 4.f;
    }

    public float rightBorder() {
        return 3 * parentWidth / 4.f;
    }

    public void onSelected(final boolean isLeft,
                           float exitY, long duration) {

        isAnimationRunning = true;
        float exitX;
        if (isLeft) {
            exitX = -objectW - getRotationWidthOffset();
        } else {
            exitX = parentWidth + getRotationWidthOffset();
        }

        this.frame.animate()
                .setDuration(duration)
                .setInterpolator(new AccelerateInterpolator())
                .x(exitX)
                .y(exitY)
                .setListener(new AnimatorListenerAdapter() {
                    @Override
                    public void onAnimationEnd(Animator animation) {
                        if (isLeft) {
                            mFlingListener.onCardExited();
                            mFlingListener.leftExit(dataObject);
                        } else {
                            mFlingListener.onCardExited();
                            mFlingListener.rightExit(dataObject);
                        }
                        isAnimationRunning = false;
                    }
                })
                .rotation(getExitRotation(isLeft));
    }

    /**
     * Starts a default left exit animation.
     */
    public void selectLeft() {
        if (!isAnimationRunning)
            onSelected(true, objectY, 200);
    }

    /**
     * Starts a default right exit animation.
     */
    public void selectRight() {
        if (!isAnimationRunning)
            onSelected(false, objectY, 200);
    }

    private float getExitPoint(int exitXPoint) {
        float[] x = new float[2];
        x[0] = objectX;
        x[1] = aPosX;

        float[] y = new float[2];
        y[0] = objectY;
        y[1] = aPosY;

        LinearRegression regression = new LinearRegression(x, y);

        //Your typical y = ax+b linear regression
        return (float) regression.slope() * exitXPoint + (float) regression.intercept();
    }

    private float getExitRotation(boolean isLeft) {
        float rotation = BASE_ROTATION_DEGREES * 2.f * (parentWidth - objectX) / parentWidth;
        if (touchPosition == TOUCH_BELOW) {
            rotation = -rotation;
        }
        if (isLeft) {
            rotation = -rotation;
        }
        return rotation;
    }

    /**
     * When the object rotates it's width becomes bigger.
     * The maximum width is at 45 degrees.
     * <p/>
     * The below method calculates the width offset of the rotation.
     */
    private float getRotationWidthOffset() {
        return objectW / MAX_COS - objectW;
    }

    public void setRotationDegrees(float degrees) {
        this.BASE_ROTATION_DEGREES = degrees;
    }

    public boolean isTouching() {
        return this.mActivePointerId != INVALID_POINTER_ID;
    }

    public PointF getLastPoint() {
        return new PointF(this.aPosX, this.aPosY);
    }

    protected interface FlingListener {
        void onCardExited();

        void leftExit(Object dataObject);

        void rightExit(Object dataObject);

        void onClick(Object dataObject);

        void onScroll(float scrollProgressPercent);
    }

}

[hy9be]

@Nidre why not send a PR?

[Ludomancer]

@hy9be I haven't really done any optimizations and tested this code thoroughly. I have already made many changes after that. But I could push those changes. I haven't really contributed to anyoneelses repo before. Do you know a guide that would explain how create a pull request? I would be happy to send one.

[hy9be]

Got it.

For PR, just do a fork and then follow the instruction here: https://help.github.com/articles/creating-a-pull-request/

[Ludomancer]

Cool. I will take a look into it when I'm free. I have done some customizations with animations and other systems in my own codebase. Might take while to pick stuff that is relevant only for this library. But will definitely try to create a PR as soon as I can.

[hy9be]

Cool man.

[hy9be]

@Diolor Do you think this is a valid fix?

[lushan1314]

that's great! I met some problems , When I gave childview set the click event is invalid. but can handle all click event at OnItemClicked. it looks fine.thank you!

[Diolor]

Will close this thread for the sake of #169 . It's implemented on v2.0