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Visualiseur de hauteur dynamique

J'essaie de créer un viewpager personnalisé dans une vue de défilement personnalisée qui enveloppe de manière dynamique la hauteur de l'enfant en cours.

package com.example.vihaan.dynamicviewpager;

import Android.content.Context;
import Android.util.AttributeSet;
import Android.view.GestureDetector;
import Android.view.MotionEvent;
import Android.widget.ScrollView;

    /**
     * Created by vihaan on 1/9/15.
     */
    public class CustomScrollView extends ScrollView {

        private GestureDetector mGestureDetector;

        public CustomScrollView(Context context, AttributeSet attrs) {
            super(context, attrs);
            mGestureDetector = new GestureDetector(context, new YScrollDetector());
            setFadingEdgeLength(0);
        }

        @Override
        public boolean onInterceptTouchEvent(MotionEvent ev) {
            return super.onInterceptTouchEvent(ev)
                    && mGestureDetector.onTouchEvent(ev);
        }

        // Return false if we're scrolling in the x direction
        class YScrollDetector extends GestureDetector.SimpleOnGestureListener {
            @Override
            public boolean onScroll(MotionEvent e1, MotionEvent e2,
                                    float distanceX, float distanceY) {
                return (Math.abs(distanceY) > Math.abs(distanceX));
            }
        }
    }

CustomPager

/**
 * Created by vihaan on 1/9/15.
 */
public class CustomPager extends ViewPager {

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

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

    @Override
    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        boolean wrapHeight = MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST;

        final View tab = getChildAt(0);
        int width = getMeasuredWidth();
        int tabHeight = tab.getMeasuredHeight();

        if (wrapHeight) {
            // Keep the current measured width.
            widthMeasureSpec = MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY);
        }

        int fragmentHeight = measureFragment(((Fragment) getAdapter().instantiateItem(this, getCurrentItem())).getView());
        heightMeasureSpec = MeasureSpec.makeMeasureSpec(tabHeight + fragmentHeight + (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 50, getResources().getDisplayMetrics()), MeasureSpec.AT_MOST);

        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    public int measureFragment(View view) {
        if (view == null)
            return 0;

        view.measure(0, 0);
        return view.getMeasuredHeight();
    }
}

MyPagerAdapter

public class MyPagerAdapter extends FragmentPagerAdapter {

    private List<Fragment> fragments;

    public MyPagerAdapter(FragmentManager fm) {
        super(fm);
        this.fragments = new ArrayList<Fragment>();
        fragments.add(new FirstFragment());
        fragments.add(new SecondFragment());
        fragments.add(new ThirdFragment());
        fragments.add(new FourthFragment());
    }

    @Override
    public Fragment getItem(int position) {
        return fragments.get(position);
    }

    @Override
    public int getCount() {
        return fragments.size();
    }
}

J'espérais que cela engloberait la taille des fragments actuels, mais cela ne prend que la taille du premier enfant en considération.

Exemple de projet github: https://github.com/VihaanVerma89/DynamicViewPager

25
Vihaan Verma

@ abhishek's ans fait ce qui est requis mais le code ci-dessous ajoute également une animation lors du changement de hauteur

public class WrappingViewPager extends ViewPager {

    private Boolean mAnimStarted = false;

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

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

    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        if(!mAnimStarted && null != getAdapter()) {
            int height = 0;
            View child = ((FragmentPagerAdapter) getAdapter()).getItem(getCurrentItem()).getView();
            if (child != null) {
                child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
                height = child.getMeasuredHeight();
                if (VersionUtils.isJellyBean() && height < getMinimumHeight()) {
                    height = getMinimumHeight();
                }
            }

            // Not the best place to put this animation, but it works pretty good.
            int newHeight = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
            if (getLayoutParams().height != 0 && heightMeasureSpec != newHeight) {
                    final int targetHeight = height;
                    final int currentHeight = getLayoutParams().height;
                    final int heightChange = targetHeight - currentHeight;

                    Animation a = new Animation() {
                        @Override
                        protected void applyTransformation(float interpolatedTime, Transformation t) {
                            if (interpolatedTime >= 1) {
                                getLayoutParams().height = targetHeight;
                            } else {
                                int stepHeight = (int) (heightChange * interpolatedTime);
                                getLayoutParams().height = currentHeight + stepHeight;
                            }
                            requestLayout();
                        }

                        @Override
                        public boolean willChangeBounds() {
                            return true;
                        }
                    };

                    a.setAnimationListener(new Animation.AnimationListener() {
                        @Override
                        public void onAnimationStart(Animation animation) {
                            mAnimStarted = true;
                        }

                        @Override
                        public void onAnimationEnd(Animation animation) {
                            mAnimStarted = false;
                        }

                        @Override
                        public void onAnimationRepeat(Animation animation) {
                        }
                    });

                    a.setDuration(1000);
                    startAnimation(a);
                    mAnimStarted = true;
            } else {
                heightMeasureSpec = newHeight;
            }
        }

        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
}
23
Vihaan Verma

Faites quelques ajustements dans votre code et cela fonctionne bien maintenant.

1] La fonction onMeasure n'était pas appropriée. Utilisez la logique ci-dessous

@Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    if (mCurrentView == null) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        return;
    }
    int height = 0;
    mCurrentView.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
    int h = mCurrentView.getMeasuredHeight();
    if (h > height) height = h;
    heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);

    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}

2] ViewPager doit être ré-mesuré chaque fois qu'une page est modifiée. Un bon endroit pour faire ceci est setPrimaryItem fonction de PagerAdapter

@Override
    public void setPrimaryItem(ViewGroup container, int position, Object object) {
        super.setPrimaryItem(container, position, object);
        if (position != mCurrentPosition) {
            Fragment fragment = (Fragment) object;
            CustomPager pager = (CustomPager) container;
            if (fragment != null && fragment.getView() != null) {
                mCurrentPosition = position;
                pager.measureCurrentView(fragment.getView());
            }
        }
    }

Voici le lien vers le projet GitHub avec ces modifications: https://github.com/vabhishek/WrapContentViewPagerDemo

56
Abhishek V

Juste au cas où quelqu'un d'autre trouve ce post comme moi. Version travaillée sans bug de hauteur zéro initialement:

public class DynamicHeightViewPager extends ViewPager {
    private View mCurrentView;

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

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

    @Override
    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        if (mCurrentView != null) {
            mCurrentView.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));

            int height = Math.max(0, mCurrentView.getMeasuredHeight());
            heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);

            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }

    public void measureCurrentView(View currentView) {
        mCurrentView = currentView;
        requestLayout();
    }
}

Et utilisé dans FragmentPagerAdapter personnalisé, comme ceci

public abstract class AutoheightFragmentPagerAdapter extends FragmentPagerAdapter {
    private int mCurrentPosition = -1;

    public AutoheightFragmentPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public void setPrimaryItem(ViewGroup container, int position, Object object) {
        super.setPrimaryItem(container, position, object);

        if (position != mCurrentPosition && container instanceof DynamicHeightViewPager) {
            Fragment fragment = (Fragment) object;
            DynamicHeightViewPager pager = (DynamicHeightViewPager) container;

            if (fragment != null && fragment.getView() != null) {
                mCurrentPosition = position;
                pager.measureCurrentView(fragment.getView());
            }
        }
    }
}
12
ITurchenko

En ajoutant à la solution de @ vihaan, si vous avez un PagerTitleStrip ou un PagetTabStrip, vous pouvez ajouter ceci

// Account for pagerTitleStrip or pagerTabStrip
View tabStrip = getChildAt(0);
if (tabStrip instanceof PagerTitleStrip) {
    tabStrip.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(getMeasuredWidth(), MeasureSpec.UNSPECIFIED));
    height += tabStrip.getMeasuredHeight();
}

juste avant de commencer l'animation (avant le commentaire 

  // Ce n'est pas le meilleur endroit pour mettre cette animation, mais ça marche plutôt bien .

de sorte que la hauteur de la bande est prise en compte.

3
talosdev
public class WrapContentViewPager extends ViewPager {
private Boolean mAnimStarted = false;

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

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

@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    if (!mAnimStarted && null != getAdapter()) {
        int height = 0;
        View child = ((CommonViewPagerAdapter) getAdapter()).getItem(getCurrentItem()).getView();
        if (child != null) {
            child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
            height = child.getMeasuredHeight();
            if (height < getMinimumHeight()) {
                height = getMinimumHeight();
            }
        }

        // Not the best place to put this animation, but it works pretty good.
        int newHeight = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
        if (getLayoutParams().height != 0 && heightMeasureSpec != newHeight) {
            final int targetHeight = height;
            final int currentHeight = getLayoutParams().height;
            final int heightChange = targetHeight - currentHeight;

            Animation a = new Animation() {
                @Override
                protected void applyTransformation(float interpolatedTime, Transformation t) {
                    if (interpolatedTime >= 1) {
                        getLayoutParams().height = targetHeight;
                    } else {
                        int stepHeight = (int) (heightChange * interpolatedTime);
                        getLayoutParams().height = currentHeight + stepHeight;
                    }
                    requestLayout();
                }

                @Override
                public boolean willChangeBounds() {
                    return true;
                }
            };

            a.setAnimationListener(new Animation.AnimationListener() {
                @Override
                public void onAnimationStart(Animation animation) {
                    mAnimStarted = true;
                }

                @Override
                public void onAnimationEnd(Animation animation) {
                    mAnimStarted = false;
                }

                @Override
                public void onAnimationRepeat(Animation animation) {
                }
            });

            a.setDuration(100);
            startAnimation(a);
            mAnimStarted = true;
        } else {
            heightMeasureSpec = newHeight;
        }
    }

    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}

=============================

wrapContentViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        }

        @Override
        public void onPageSelected(int position) {
            wrapContentViewPager.measure(wrapContentViewPager.getMeasuredWidth(), wrapContentViewPager.getMeasuredHeight());
        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

entrez la description de l'image ici

0
The Xuan Bui