Android : déplacer une vue au toucher (ACTION_MOVE)

Question

Je voudrais faire un contrôle simple : un conteneur avec une vue à l'intérieur. Si je touche le conteneur et que je bouge le doigt, je veux déplacer la vue pour qu'elle suive mon doigt.

Quel type de conteneur (aménagement) dois-je utiliser ? Comment faire ?

Je n'ai pas besoin d'utiliser une surface, mais une disposition simple.

Answer 1

Même implémentation en Kotlin

    rightPanel.setOnTouchListener(View.OnTouchListener { view, event ->
        when (event?.action) {
            MotionEvent.ACTION_DOWN -> {

                rightDX = view!!.x - event.rawX
                // rightDY = view!!.getY() - event.rawY;

            }
            MotionEvent.ACTION_MOVE -> {

                var displacement = event.rawX + rightDX

                view!!.animate()
                        .x(displacement)
                        // .y(event.getRawY() + rightDY)
                        .setDuration(0)
                        .start()
            }
            else -> { // Note the block
                return@OnTouchListener false
            }
        }
        true
 })

Answer 2

Je recommande d'utiliser view.translationX et view.translationY pour déplacer vos vues.

Un extrait de Kotlin :

yourView.translationX = xTouchCoordinate
yourView.translationY = yTouchCoordinate

Answer 3

Dans le code ci-dessous, j'ai créé quelque chose appelé le RegionView ( git ), qui est un conteneur réutilisable chargé de gérer les opérations de glisser et de zoom pour chacun de ses enfants imbriqués.

Ici, nous manipulons le top y left coefficients d'un enfant View 's LayoutParams pour simuler le mouvement autour du diagramme. En découplant l'interprétation de la manipulation de ce qui est compris comme une opération de glisser, et ce qui est déterminé comme une opération d'échelle, nous pouvons fournir une manipulation fiable d'un enfant View .

package com.zonal.regionview;

import android.annotation.TargetApi;
import android.content.Context;
import android.os.Build;
import android.os.Vibrator;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.widget.RelativeLayout;

import java.util.HashMap;
import java.util.Map;

/**
 * Created by Alexander Thomas (@Cawfree) on 20/07/2017.
 */

/** Enables users to customize Regions Of Interest on a Canvas. */
public class RegionView extends RelativeLayout implements View.OnTouchListener, GestureDetector.OnGestureListener, ScaleGestureDetector.OnScaleGestureListener {

    /* Member Variables. */
    private final GestureDetector      mGestureDetector;
    private final ScaleGestureDetector mScaleGestureDetector;
    private final Map<Integer, View>   mViewMap;
    private       boolean              mScaling;
    private       float                mScale;
    private       boolean              mWrapContent;
    private       boolean              mDropOnScale;

    public RegionView(Context context) {
        // Implement the Parent.
        super(context);
        // Initialize Member Variables.
        this.mGestureDetector      = new GestureDetector(context, this);
        this.mViewMap              = new HashMap<>();
        this.mScaleGestureDetector = new ScaleGestureDetector(context, this);
        this.mScaling              = false;
        this.mScale                = Float.NaN;
        this.mWrapContent          = false;
        this.mDropOnScale          = false;
        // Register ourself as the OnTouchListener.
        this.setOnTouchListener(this);
    }

    public RegionView(Context context, @Nullable AttributeSet attrs) {
        // Implement the Parent.
        super(context, attrs);
        // Initialize Member Variables.
        this.mGestureDetector      = new GestureDetector(context, this);
        this.mViewMap              = new HashMap<>();
        this.mScaleGestureDetector = new ScaleGestureDetector(context, this);
        this.mScaling              = false;
        this.mWrapContent          = false;
        this.mDropOnScale          = false;
        // Register ourself as the OnTouchListener.
        this.setOnTouchListener(this);
    }

    public RegionView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        // Implement the Parent.
        super(context, attrs, defStyleAttr);
        // Initialize Member Variables.
        this.mGestureDetector      = new GestureDetector(context, this);
        this.mViewMap              = new HashMap<>();
        this.mScaleGestureDetector = new ScaleGestureDetector(context, this);
        this.mScaling              = false;
        this.mWrapContent          = false;
        this.mDropOnScale          = false;
        // Register ourself as the OnTouchListener.
        this.setOnTouchListener(this);
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public RegionView(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        // Implement the Parent.
        super(context, attrs, defStyleAttr, defStyleRes);
        // Initialize Member Variables.
        this.mGestureDetector      = new GestureDetector(context, this);
        this.mViewMap              = new HashMap<>();
        this.mScaleGestureDetector = new ScaleGestureDetector(context, this);
        this.mScaling              = false;
        this.mWrapContent          = false;
        this.mDropOnScale          = false;
        // Register ourself as the OnTouchListener.
        this.setOnTouchListener(this);
    }

    @Override
    public boolean onTouch(final View v, final MotionEvent event) {
        // Calculate the PointerId.
        final int lPointerId = event.getPointerId(event.getActionIndex());
        // Handle the TouchEvent.
        this.getGestureDetector().onTouchEvent(event);
        this.getScaleGestureDetector().onTouchEvent(event);
        // Did the user release a pointer?
        if(event.getAction() == MotionEvent.ACTION_UP) {
            // Was there a View associated with this Action?
            final View lView = this.getViewMap().get(lPointerId);
            // Does the View exist?
            if(lView != null) {
                // Remove the View from the Map.
                this.getViewMap().remove(lPointerId); /** TODO: Provide a Callback? */
            }
        }
        // Consume all events for now.
        return true;
    }

    @Override
    public boolean onDown(MotionEvent e) {
        // Calculate the PointerId.
        final Integer lPointerId = Integer.valueOf(e.getPointerId(e.getActionIndex()));
        // Fetch the View.
        final View    lView      = this.getViewFor(Math.round(e.getRawX()), Math.round(e.getRawY()));
        // Is it valid?
        if(lView != null) {
            // Watch the View.
            this.getViewMap().put(lPointerId, lView);
            // Configure the Anchor.
            lView.setPivotX(0);
            lView.setPivotY(0);
            // Assert that we handled the event.
            return true;
        }
        // Assert that we ignored the event.
        return false;
    }

    @Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
        // Are we not scaling?
        if(!this.isScaling()) {
            // Calculate the PointerId.
            final Integer lPointerId = Integer.valueOf(e1.getPointerId(e1.getActionIndex()));
            // Fetch the View.
            final View    lView      = this.getViewMap().get(lPointerId);
            // Is the scroll valid for a given View?
            if(lView != null) {
                // Calculate the Scaled Width and Height of the View.
                final float lWidth    = lView.getWidth()  * lView.getScaleX();
                final float lHeight   = lView.getHeight() * lView.getScaleY();
                // Declare the initial position.
                final int[] lPosition = new int[] { (int)(e2.getX() - ((lWidth)  / 2)), (int)(e2.getY() - ((lHeight) / 2)) };
                // Are we wrapping content?
                if(this.isWrapContent()) {
                    // Wrap the Position.
                    this.onWrapContent(lPosition, lWidth, lHeight);
                }
                // Update the Drag.
                this.onUpdateDrag(lView, lPosition);
            }
            // Assert we handled the scroll.
            return true;
        }
        // Otherwise, don't permit scrolling. Don't consume the MotionEvent.
        return false;
    }

    /** Forces X/Y values to be coerced within the confines of the RegionView. */
    private final void onWrapContent(final int[] pPosition, final float pWidth, final float pHeight) {
        // Limit the parameters. (Top-Left)
        pPosition[0] = Math.max(pPosition[0], 0);
        pPosition[1] = Math.max(pPosition[1],  0);
        // Limit the parameters. (Bottom-Right)
        pPosition[0] = Math.min(pPosition[0], (int)(this.getWidth()  - pWidth));
        pPosition[1] = Math.min(pPosition[1], (int)(this.getHeight() - pHeight));
    }

    /** Updates the Drag Position of a child View within the Layout. Implicitly, we update the LayoutParams of the View. */
    private final void onUpdateDrag(final View pView, final int pLeft, final int pTop) {
        // Allocate some new MarginLayoutParams.
        final MarginLayoutParams lMarginLayoutParams = new MarginLayoutParams(pView.getLayoutParams());
        // Update the Margin.
        lMarginLayoutParams.setMargins(pLeft, pTop, 0, 0);
        // Refactor the MarginLayoutParams into equivalent LayoutParams for the RelativeLayout.
        pView.setLayoutParams(new RelativeLayout.LayoutParams(lMarginLayoutParams));
    }

    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        // Calculate the ScaleFactor.
              float lScaleFactor = detector.getScaleFactor() - 1;
        // Fetch the Scaled View.
        final View  lView        = this.getViewMap().entrySet().iterator().next().getValue();
        // Update the ScaleFactor.
        final float lScale       = this.getScale() + lScaleFactor;
        // Calculate the Proposed Width and Height.
        final int   lWidth  = Math.round(lView.getWidth()  * lScale);
        final int   lHeight = Math.round(lView.getHeight() * lScale);
        // Is the View already too large for wrap content?
        if(lWidth >= this.getWidth() || lHeight >= this.getHeight()) {
            // Don't update the scale.
            return false;
        }
        // Persist this Scale for the View.
        lView.setScaleX(lScale);
        lView.setScaleY(lScale);
        // Assign the Scale.
        this.setScale(lScale);
        // Compute the Position.
        final int[] lPosition = new int[] { Math.round(detector.getFocusX()) - (lWidth / 2), Math.round(detector.getFocusY()) - (lHeight / 2) };
        // Are we wrapping the Position?
        if(this.isWrapContent()) {
            // Wrap the Position.
            this.onWrapContent(lPosition, lWidth, lHeight);
        }
        // Update the Drag.
        this.onUpdateDrag(lView, lPosition);
        // Assert that we handled the scale.
        return true;
    }

    /** Update the Drag. */
    private final void onUpdateDrag(final View pView, final int[] pPosition) {
        // Call the sub-implementation.
        this.onUpdateDrag(pView, pPosition[0], pPosition[1]);
    }

    @Override
    public boolean onScaleBegin(ScaleGestureDetector detector) { 
        // Is the user not dragging at all?
        if(this.getViewMap().size() == 1) {
            // Fetch the View.
            final View lView = this.getViewMap().entrySet().iterator().next().getValue();
            // Initialize the Scale.
            this.setScale(lView.getScaleX()); 
            // Assert that we've started scaling.
            this.setScaling(true);
            // Inform the callback.
            return true;
        }
        // Otherwise, don't allow scaling.
        return false;
    }

    @Override
    public void onScaleEnd(ScaleGestureDetector detector) {
        // Were we scaling?
        if(this.isScaling()) {
            // Assert that we've stopped scaling.
            this.setScaling(false);
            // Reset the Scale.
            this.setScale(Float.NaN);
            // Should we stop dragging now that we've finished scaling?
            if(this.isDropOnScale()) {
                // Clear the ViewMap.
                this.getViewMap().clear();
            }
        }
    }

    /** Returns the View colliding with the given co-ordinates. */
    private final View getViewFor(final int pX, final int pY) {
        // Declare the LocationBuffer.
        final int[] lLocationBuffer = new int[2];
        // Iterate the Views.
        for(int i = 0; i < this.getChildCount(); i++) {
            // Fetch the child View.
            final View lView = this.getChildAt(i);
            // Fetch its absolute position.
            lView.getLocationOnScreen(lLocationBuffer);
            // Determine if the MotionEvent collides with the View.
            if(pX > lLocationBuffer[0] && pY > lLocationBuffer[1] && (pX < lLocationBuffer[0] + (lView.getWidth() * lView.getScaleX())) && (pY < lLocationBuffer[1] + (lView.getHeight() * lView.getScaleY()))) {
                // Return the View.
                return lView;
            }
        }
        // We couldn't find a View.
        return null;
    }

    /* Unused Overrides. */
    @Override public void      onShowPress(MotionEvent e) {  }
    @Override public boolean onSingleTapUp(MotionEvent e) {
        return false;
    }
    @Override public void      onLongPress(MotionEvent e) { }
    @Override public boolean       onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { return false; }

    /* Getters and Setters. */
    private final GestureDetector getGestureDetector() {
        return this.mGestureDetector;
    }

    private final ScaleGestureDetector getScaleGestureDetector() {
        return this.mScaleGestureDetector;
    }

    private final Map<Integer, View> getViewMap() {
        return this.mViewMap;
    }

    private final void setScaling(final boolean pIsScaling) {
        this.mScaling = pIsScaling;
    }

    private final boolean isScaling() {
        return this.mScaling;
    }

    private final void setScale(final float pScale) {
        this.mScale = pScale;
    }

    private final float getScale() {
        return this.mScale;
    }

    /** Defines whether we coerce the drag and zoom of child Views within the confines of the Layout. */
    public final void setWrapContent(final boolean pIsWrapContent) {
        this.mWrapContent = pIsWrapContent;
    }

    public final boolean isWrapContent() {
        return this.mWrapContent;
    }

    /** Defines whether a drag operation is considered 'finished' once the user finishes scaling a view. */
    public final void setDropOnScale(final boolean pIsDropOnScale) {
        this.mDropOnScale = pIsDropOnScale;
    }

    public final boolean isDropOnScale() {
        return this.mDropOnScale;
    }

}

Je montre ici un exemple d'utilisation :

package com.zonal.regionview;

import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.AnalogClock;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // Allocate a RegionView.
        final RegionView lRegionView = new RegionView(this);
        // Add some example items to drag.
        lRegionView.addView(new AnalogClock(this));
        lRegionView.addView(new AnalogClock(this));
        lRegionView.addView(new AnalogClock(this));
        // Assert that we only want to drag Views within the confines of the RegionView.
        lRegionView.setWrapContent(true);
        // Assert that after we've finished scaling a View, we want to stop being able to drag it until a new drag is started.
        lRegionView.setDropOnScale(true);
        // Look at the RegionView.
        this.setContentView(lRegionView);
    }

}

Answer 4

Dans cet exemple, vous pouvez déplacer la vue à l'intérieur de ses limites parentales, quelle que soit sa taille, réaliser une animation sans défaut et capter les clics.

La raison pour laquelle cette solution est supérieure aux autres commentaires est que cette approche utilise une Pavé directionnel qui se calcule lui-même et ne s'appuie pas sur les positions de la vue, ce qui est à l'origine de nombreux bugs.

// we could use this gameobject as a wrapper that controls the touch event of the component(the table)
// and like so, we can have a click event and touch events
public abstract class GameObjectStackOverflow {

private static final int CLICK_DURATION = 175;
protected View view;
protected ViewGroup container;
protected Context mContext;

private boolean onMove = false;
private boolean firstAnimation = true;
private Animator.AnimatorListener listener;

protected float parentWidth;
protected float parentHeight;

protected float xmlHeight;
protected float xmlWidth;

// Those are the max bounds
// whiting the xmlContainer
protected float xBoundMax;
protected float yBoundMax;

// This variables hold the target
// ordinates for the next
// animation in case an animation
// is already in progress.
protected float targetX;
protected float targetY;

private float downRawX;
private float downRawY;

public GameObjectStackOverflow(@NonNull Context context, @NonNull ViewGroup container)
{
    mContext = context;
    this.container = container;
}

// This method is the reason the constructor
// does not get view to work with in the first
// place. This method helps us to work with
// android main thread in such way that we
// separate the UI stuff from the technical
// stuff
protected View initGraphicView(@NonNull LayoutInflater inflater, int resource, boolean add)
{
    view = inflater.inflate(resource, container, add);
    view.post(getOnViewAttach());
    view.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            return onTouchEvent(event);
        }
    });
    return view;
}

// This method attach an existing
// view that is already inflated
protected void attachGraphicView(@NonNull final View view)
{
    this.view = view;
    view.post(getOnViewAttach());
}

// This method is anti-boiler code.
// attaching runnable to the view
// task queue to finish the
// initialization of the game object.
private Runnable getOnViewAttach()
{
    return new Runnable() {
        @Override
        public void run() {
            parentHeight = container.getHeight();
            parentWidth = container.getWidth();
            view.setX(currentX);
            view.setY(currentY);
        }
    };
}

private void click() {
    // recover the view to the previous location [not needed]
    // not needed
    //view.animate()
    //    .x(prevPosX)
    //    .y(prevPosY)
    //    .setDuration(0)
    //    .start();
}

// maybe restore the View view, Motion event
public boolean onTouchEvent(MotionEvent event)
{
    view.getParent().requestDisallowInterceptTouchEvent(true);
    //if(!selected) return false;
    switch (event.getAction())
    {
        case MotionEvent.ACTION_UP:
            if (event.getEventTime() - event.getDownTime() < CLICK_DURATION) click(); // are you missing break here?
            onMove = false;
            // if needed to update network entity do it here
            break;
        case MotionEvent.ACTION_DOWN:
            firstAnimation = true;
            xBoundMax = parentWidth - xmlWidth;
            yBoundMax = parentHeight - xmlHeight;
            downRawX = event.getRawX();
            downRawY = event.getRawY();
            break;

        case MotionEvent.ACTION_MOVE:
            if (!onMove) {
                if (event.getEventTime() - event.getDownTime() < CLICK_DURATION) break;
                else onMove = true;
            }

            // Calculating the position the
            // view should be posed at.
            float offsetX = event.getRawX() - downRawX;
            float offsetY = event.getRawY() - downRawY;
            downRawX = event.getRawX();
            downRawY = event.getRawY();
            targetX = currentX + offsetX;
            targetY = currentY + offsetY;

            // Checking if view
            // is within parent bounds
            if (targetX > parentWidth - xmlWidth) targetX = xBoundMax;
            else if (targetX < 0) targetX = 0;
            if (targetY > parentHeight - xmlHeight) targetY = yBoundMax;
            else if (targetY < 0) targetY = 0;

            // This check is becuase the user may just click on the view
            // So if it's a not a click, animate slowly but fastly
            // to the desired position
            if (firstAnimation) {
                firstAnimation = false;
                animate(70, getNewAnimationListener());
                break;
            }

            if (listener != null) break;
            animate(0, null);
            break;

        case MotionEvent.ACTION_BUTTON_PRESS:
        default:
            return false;
    }
    return true;
}

// this method gets used only in
// one place. it's wrapped in a method
// block because i love my code like
// i love women - slim, sexy and smart.
public Animator.AnimatorListener getNewAnimationListener() {
    listener = new Animator.AnimatorListener() {
        @Override public void onAnimationStart(Animator animation) { }
        @Override public void onAnimationCancel(Animator animation) { }
        @Override public void onAnimationRepeat(Animator animation) { }
        @Override public void onAnimationEnd(Animator animation) {
            animation.removeListener(listener);
            listener = null;
            view.setAnimation(null);
            animate(0, null);
        }
    };
    return listener;
}

float currentX = 0, currentY = 0;

private void animate(int duration, @Nullable Animator.AnimatorListener listener) {
    view.animate()
            .x(targetX)
            .y(targetY)
            .setDuration(duration)
            .setListener(listener)
            .start();
        currentX = targetX;
        currentY = targetY;
}

protected void setSize(float width, float height)
{
    xmlWidth = width;
    xmlHeight = height;
    RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) view.getLayoutParams();
    layoutParams.width = (int) width;
    layoutParams.height = (int) height;
    view.setLayoutParams(layoutParams);
}

public View getView() {
    return view;
}

//This interface catches the onclick even
// that happened and need to decide what to do.
public interface GameObjectOnClickListener {
    void onGameObjectClick(GameObjectStackOverflow object);
}

public float getXmlWidth() {
    return xmlWidth;
}

public float getXmlHeight() {
    return xmlHeight;
}
}

Cette version a été dépouillée du gros matériel qui avait l'habitude d'avoir une entité réseau qui est mise à jour en direct et ainsi de suite, cela devrait fonctionner.

---

vous devriez l'utiliser de cette façon

public class Tree extends GameObject
{
    public Tree(Context context, ViewGroup container, View view, int width, int height) {
        super(context, manager, container);
        attachGraphicView(view);
        super.setSize(_width, _height);
    }
}

et que

mTree= new Tree(mContext, mContainer, xmlTreeView);     
mTree.getView().setOnTouchListener(getOnTouchListener(mTree));

vous devriez avoir ceci aussi mais cela peut être facilement enlevé

//Construct new OnTouchListener that reffers to the gameobject ontouchevent
private View.OnTouchListener getOnTouchListener(final GameObject object) {
    return new View.OnTouchListener() {
        @Override
        public boolean onTouch(View view, MotionEvent event) {
            return object.onTouchEvent(event);
        }
    };
}

---

Si le conteneur se trouve à l'intérieur d'un ScrollView ou d'un ScrollView à double dimension, vous devez ajouter cette ligne au onTouch

view.getParent().requestDisallowInterceptTouchEvent(true);

Answer 5

Modification d'une solution fournie par @Vyacheslav Shylkin pour supprimer les dépendances des nombres saisis manuellement.

import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewTreeObserver;
import android.widget.ImageView;
import android.widget.RelativeLayout;

public class MainActivity extends Activity implements View.OnTouchListener
{
    private int       _xDelta;
    private int       _yDelta;
    private int       _rightMargin;
    private int       _bottomMargin;
    private ImageView _floatingView;

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

        this._floatingView = (ImageView) findViewById(R.id.textView);

        this._floatingView.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener()
        {
            @Override
            public boolean onPreDraw()
            {
                if (_floatingView.getViewTreeObserver().isAlive())
                    _floatingView.getViewTreeObserver().removeOnPreDrawListener(this);

                updateLayoutParams(_floatingView);
                return false;
            }
        });

        this._floatingView.setOnTouchListener(this);
    }

    private void updateLayoutParams(View view)
    {
        this._rightMargin = -view.getMeasuredWidth();
        this._bottomMargin = -view.getMeasuredHeight();

        RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(view.getMeasuredWidth(), view.getMeasuredHeight());
        layoutParams.bottomMargin = this._bottomMargin;
        layoutParams.rightMargin = this._rightMargin;

        view.setLayoutParams(layoutParams);
    }

    @Override
    public boolean onTouch(View view, MotionEvent event)
    {
        if (view == this._floatingView)
        {
            final int X = (int) event.getRawX();
            final int Y = (int) event.getRawY();

            switch (event.getAction() & MotionEvent.ACTION_MASK)
            {
                case MotionEvent.ACTION_DOWN:
                    RelativeLayout.LayoutParams lParams = (RelativeLayout.LayoutParams) view.getLayoutParams();
                    this._xDelta = X - lParams.leftMargin;
                    this._yDelta = Y - lParams.topMargin;
                    break;

                case MotionEvent.ACTION_MOVE:
                    RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) view.getLayoutParams();
                    layoutParams.leftMargin = X - this._xDelta;
                    layoutParams.topMargin = Y - this._yDelta;
                    layoutParams.rightMargin = this._rightMargin;
                    layoutParams.bottomMargin = this._bottomMargin;
                    view.setLayoutParams(layoutParams);
                    break;
            }

            return true;
        }
        else
        {
            return false;
        }
    }
}