Android RecyclerView avec GridLayoutManager pour que l'élément s'étende sur plusieurs lignes

Question

J'ai une collection de photos, et j'utilise un logiciel de gestion des photos. RecyclerView pour les afficher. Je veux que le premier élément de mon RecyclerView couvrir 2 colonnes ET 2 lignes :

Je sais que je peux couvrir 2 colonnes avec setSpanSizeLookup :

GridLayoutManager gridLayoutManager = new GridLayoutManager(this, 3);
gridLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
    @Override
    public int getSpanSize(int position) {
        if (position == 0) {
            return 2;
        } else {
            return 1;
        }
    }
});

mais comment puis-je faire en sorte que le premier élément s'étende sur deux rangées également ?

J'ai essayé de définir une hauteur différente pour le premier élément en gonflant une mise en page différente avec une hauteur double de celle des autres, mais cela a eu pour conséquence que tous les éléments de la même ligne que le premier élément ont également été étirés à cette hauteur :

@Override
public ProfilePicViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View itemView;
    if (viewType == TYPE_MAIN_PHOTO) {
        itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_view_main_profile_photo, parent, false);
    } else {
        itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_view_profile_photo, parent, false);
    }
    return new ProfilePicViewHolder(itemView);
}

Answer 1

Vous ne pouvez pas obtenir ce comportement avec GridLayoutManager parce qu'il ne prend en charge que le recouvrement de plusieurs colonnes.

Nick Butcher est actuellement en train de mettre en place une SpannedGridLayoutManager qui fait exactement ce que vous voulez. Il vous permet de couvrir plusieurs lignes et colonnes en même temps. L'implémentation est encore en cours, mais elle fonctionne déjà très bien.

SpannedGridLayoutManager.java

package io.plaidapp.ui.recyclerview;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.PointF;
import android.graphics.Rect;
import android.support.annotation.Keep;
import android.support.annotation.NonNull;
import android.support.v7.widget.LinearSmoothScroller;
import android.support.v7.widget.RecyclerView;
import android.util.AttributeSet;
import android.util.SparseArray;
import android.view.View;
import android.view.ViewGroup;

import java.util.ArrayList;
import java.util.List;

import io.plaidapp.R;

/**
 * A {@link RecyclerView.LayoutManager} which displays a regular grid (i.e. all cells are the same
 * size) and allows simultaneous row & column spanning.
 */
public class SpannedGridLayoutManager extends RecyclerView.LayoutManager {

    private GridSpanLookup spanLookup;
    private int columns = 1;
    private float cellAspectRatio = 1f;

    private int cellHeight;
    private int[] cellBorders;
    private int firstVisiblePosition;
    private int lastVisiblePosition;
    private int firstVisibleRow;
    private int lastVisibleRow;
    private boolean forceClearOffsets;
    private SparseArray<GridCell> cells;
    private List<Integer> firstChildPositionForRow; // key == row, val == first child position
    private int totalRows;
    private final Rect itemDecorationInsets = new Rect();

    public SpannedGridLayoutManager(GridSpanLookup spanLookup, int columns, float cellAspectRatio) {
        this.spanLookup = spanLookup;
        this.columns = columns;
        this.cellAspectRatio = cellAspectRatio;
        setAutoMeasureEnabled(true);
    }

    @Keep /* XML constructor, see RecyclerView#createLayoutManager */
    public SpannedGridLayoutManager(
            Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        TypedArray a = context.obtainStyledAttributes(
                attrs, R.styleable.SpannedGridLayoutManager, defStyleAttr, defStyleRes);
        columns = a.getInt(R.styleable.SpannedGridLayoutManager_spanCount, 1);
        parseAspectRatio(a.getString(R.styleable.SpannedGridLayoutManager_aspectRatio));
        // TODO use this!
        int orientation = a.getInt(
                R.styleable.SpannedGridLayoutManager_android_orientation, RecyclerView.VERTICAL);
        a.recycle();
        setAutoMeasureEnabled(true);
    }

    public interface GridSpanLookup {
        SpanInfo getSpanInfo(int position);
    }

    public void setSpanLookup(@NonNull GridSpanLookup spanLookup) {
        this.spanLookup = spanLookup;
    }

    public static class SpanInfo {
        public int columnSpan;
        public int rowSpan;

        public SpanInfo(int columnSpan, int rowSpan) {
            this.columnSpan = columnSpan;
            this.rowSpan = rowSpan;
        }

        public static final SpanInfo SINGLE_CELL = new SpanInfo(1, 1);
    }

    public static class LayoutParams extends RecyclerView.LayoutParams {

        int columnSpan;
        int rowSpan;

        public LayoutParams(Context c, AttributeSet attrs) {
            super(c, attrs);
        }

        public LayoutParams(int width, int height) {
            super(width, height);
        }

        public LayoutParams(ViewGroup.MarginLayoutParams source) {
            super(source);
        }

        public LayoutParams(ViewGroup.LayoutParams source) {
            super(source);
        }

        public LayoutParams(RecyclerView.LayoutParams source) {
            super(source);
        }
    }

    @Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        calculateWindowSize();
        calculateCellPositions(recycler, state);

        if (state.getItemCount() == 0) {
            detachAndScrapAttachedViews(recycler);
            firstVisibleRow = 0;
            resetVisibleItemTracking();
            return;
        }

        // TODO use orientationHelper
        int startTop = getPaddingTop();
        int scrollOffset = 0;
        if (forceClearOffsets) { // see #scrollToPosition
            startTop = -(firstVisibleRow * cellHeight);
            forceClearOffsets = false;
        } else if (getChildCount() != 0) {
            scrollOffset = getDecoratedTop(getChildAt(0));
            startTop = scrollOffset - (firstVisibleRow * cellHeight);
            resetVisibleItemTracking();
        }

        detachAndScrapAttachedViews(recycler);
        int row = firstVisibleRow;
        int availableSpace = getHeight() - scrollOffset;
        int lastItemPosition = state.getItemCount() - 1;
        while (availableSpace > 0 && lastVisiblePosition < lastItemPosition) {
            availableSpace -= layoutRow(row, startTop, recycler, state);
            row = getNextSpannedRow(row);
        }

        layoutDisappearingViews(recycler, state, startTop);
    }

    @Override
    public RecyclerView.LayoutParams generateDefaultLayoutParams() {
        return new LayoutParams(
                ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT);
    }

    @Override
    public RecyclerView.LayoutParams generateLayoutParams(Context c, AttributeSet attrs) {
        return new LayoutParams(c, attrs);
    }

    @Override
    public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) {
        if (lp instanceof ViewGroup.MarginLayoutParams) {
            return new LayoutParams((ViewGroup.MarginLayoutParams) lp);
        } else {
            return new LayoutParams(lp);
        }
    }

    @Override
    public boolean checkLayoutParams(RecyclerView.LayoutParams lp) {
        return lp instanceof LayoutParams;
    }

    @Override
    public void onAdapterChanged(RecyclerView.Adapter oldAdapter, RecyclerView.Adapter newAdapter) {
        removeAllViews();
        reset();
    }

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

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

    @Override
    public int scrollVerticallyBy(int dy, RecyclerView.Recycler recycler, RecyclerView.State state){
        if (getChildCount() == 0 || dy == 0) return 0;

        int scrolled;
        int top = getDecoratedTop(getChildAt(0));

        if (dy < 0) { // scrolling content down
            if (firstVisibleRow == 0) { // at top of content
                int scrollRange = -(getPaddingTop() - top);
                scrolled = Math.max(dy, scrollRange);
            } else {
                scrolled = dy;
            }
            if (top - scrolled >= 0) { // new top row came on screen
                int newRow = firstVisibleRow - 1;
                if (newRow >= 0) {
                    int startOffset = top - (firstVisibleRow * cellHeight);
                    layoutRow(newRow, startOffset, recycler, state);
                }
            }
            int firstPositionOfLastRow = getFirstPositionInSpannedRow(lastVisibleRow);
            int lastRowTop = getDecoratedTop(
                    getChildAt(firstPositionOfLastRow - firstVisiblePosition));
            if (lastRowTop - scrolled > getHeight()) { // last spanned row scrolled out
                recycleRow(lastVisibleRow, recycler, state);
            }
        } else { // scrolling content up
            int bottom = getDecoratedBottom(getChildAt(getChildCount() - 1));
            if (lastVisiblePosition == getItemCount() - 1) { // is at end of content
                int scrollRange = Math.max(bottom - getHeight() + getPaddingBottom(), 0);
                scrolled = Math.min(dy, scrollRange);
            } else {
                scrolled = dy;
            }
            if ((bottom - scrolled) < getHeight()) { // new row scrolled in
                int nextRow = lastVisibleRow + 1;
                if (nextRow < getSpannedRowCount()) {
                    int startOffset = top - (firstVisibleRow * cellHeight);
                    layoutRow(nextRow, startOffset, recycler, state);
                }
            }
            int lastPositionInRow = getLastPositionInSpannedRow(firstVisibleRow, state);
            int bottomOfFirstRow =
                    getDecoratedBottom(getChildAt(lastPositionInRow - firstVisiblePosition));
            if (bottomOfFirstRow - scrolled < 0) { // first spanned row scrolled out
                recycleRow(firstVisibleRow, recycler, state);
            }
        }
        offsetChildrenVertical(-scrolled);
        return scrolled;
    }

    @Override
    public void scrollToPosition(int position) {
        if (position >= getItemCount()) position = getItemCount() - 1;

        firstVisibleRow = getRowIndex(position);
        resetVisibleItemTracking();
        forceClearOffsets = true;
        removeAllViews();
        requestLayout();
    }

    @Override
    public void smoothScrollToPosition(
            RecyclerView recyclerView, RecyclerView.State state, int position) {
        if (position >= getItemCount()) position = getItemCount() - 1;

        LinearSmoothScroller scroller = new LinearSmoothScroller(recyclerView.getContext()) {
            @Override
            public PointF computeScrollVectorForPosition(int targetPosition) {
                final int rowOffset = getRowIndex(targetPosition) - firstVisibleRow;
                return new PointF(0, rowOffset * cellHeight);
            }
        };
        scroller.setTargetPosition(position);
        startSmoothScroll(scroller);
    }

    @Override
    public int computeVerticalScrollRange(RecyclerView.State state) {
        // TODO update this to incrementally calculate
        if (firstChildPositionForRow == null) return 0;
        return getSpannedRowCount() * cellHeight + getPaddingTop() + getPaddingBottom();
    }

    @Override
    public int computeVerticalScrollExtent(RecyclerView.State state) {
        return getHeight();
    }

    @Override
    public int computeVerticalScrollOffset(RecyclerView.State state) {
        if (getChildCount() == 0) return 0;
        return getPaddingTop() + (firstVisibleRow * cellHeight) - getDecoratedTop(getChildAt(0));
    }

    @Override
    public View findViewByPosition(int position) {
        if (position < firstVisiblePosition || position > lastVisiblePosition) return null;
        return getChildAt(position - firstVisiblePosition);
    }

    public int getFirstVisibleItemPosition() {
        return firstVisiblePosition;
    }

    private static class GridCell {
        final int row;
        final int rowSpan;
        final int column;
        final int columnSpan;

        GridCell(int row, int rowSpan, int column, int columnSpan) {
            this.row = row;
            this.rowSpan = rowSpan;
            this.column = column;
            this.columnSpan = columnSpan;
        }
    }

    /**
     * This is the main layout algorithm, iterates over all items and places them into [column, row]
     * cell positions. Stores this layout info for use later on. Also records the adapter position
     * that each row starts at.
     * <p>
     * Note that if a row is spanned, then the row start position is recorded as the first cell of
     * the row that the spanned cell starts in. This is to ensure that we have sufficient contiguous
     * views to layout/draw a spanned row.
     */
    private void calculateCellPositions(RecyclerView.Recycler recycler, RecyclerView.State state) {
        final int itemCount = state.getItemCount();
        cells = new SparseArray<>(itemCount);
        firstChildPositionForRow = new ArrayList<>();
        int row = 0;
        int column = 0;
        recordSpannedRowStartPosition(row, column);
        int[] rowHWM = new int[columns]; // row high water mark (per column)
        for (int position = 0; position < itemCount; position++) {

            SpanInfo spanInfo;
            int adapterPosition = recycler.convertPreLayoutPositionToPostLayout(position);
            if (adapterPosition !=  RecyclerView.NO_POSITION) {
                spanInfo = spanLookup.getSpanInfo(adapterPosition);
            } else {
                // item removed from adapter, retrieve its previous span info
                // as we can't get from the lookup (adapter)
                spanInfo = getSpanInfoFromAttachedView(position);
            }

            if (spanInfo.columnSpan > columns) {
                spanInfo.columnSpan = columns; // or should we throw?
            }

            // check horizontal space at current position else start a new row
            // note that this may leave gaps in the grid; we don't backtrack to try and fit
            // subsequent cells into gaps. We place the responsibility on the adapter to provide
            // continuous data i.e. that would not span column boundaries to avoid gaps.
            if (column + spanInfo.columnSpan > columns) {
                row++;
                recordSpannedRowStartPosition(row, position);
                column = 0;
            }

            // check if this cell is already filled (by previous spanning cell)
            while (rowHWM[column] > row) {
                column++;
                if (column + spanInfo.columnSpan > columns) {
                    row++;
                    recordSpannedRowStartPosition(row, position);
                    column = 0;
                }
            }

            // by this point, cell should fit at [column, row]
            cells.put(position, new GridCell(row, spanInfo.rowSpan, column, spanInfo.columnSpan));

            // update the high water mark book-keeping
            for (int columnsSpanned = 0; columnsSpanned < spanInfo.columnSpan; columnsSpanned++) {
                rowHWM[column + columnsSpanned] = row + spanInfo.rowSpan;
            }

            // if we're spanning rows then record the 'first child position' as the first item
            // *in the row the spanned item starts*. i.e. the position might not actually sit
            // within the row but it is the earliest position we need to render in order to fill
            // the requested row.
            if (spanInfo.rowSpan > 1) {
                int rowStartPosition = getFirstPositionInSpannedRow(row);
                for (int rowsSpanned = 1; rowsSpanned < spanInfo.rowSpan; rowsSpanned++) {
                    int spannedRow = row + rowsSpanned;
                    recordSpannedRowStartPosition(spannedRow, rowStartPosition);
                }
            }

            // increment the current position
            column += spanInfo.columnSpan;
        }
        totalRows = rowHWM[0];
        for (int i = 1; i < rowHWM.length; i++) {
            if (rowHWM[i] > totalRows) {
                totalRows = rowHWM[i];
            }
        }
    }

    private SpanInfo getSpanInfoFromAttachedView(int position) {
        for (int i = 0; i < getChildCount(); i++) {
            View child = getChildAt(i);
            if (position == getPosition(child)) {
                LayoutParams lp = (LayoutParams) child.getLayoutParams();
                return new SpanInfo(lp.columnSpan, lp.rowSpan);
            }
        }
        // errrrr?
        return SpanInfo.SINGLE_CELL;
    }

    private void recordSpannedRowStartPosition(final int rowIndex, final int position) {
        if (getSpannedRowCount() < (rowIndex + 1)) {
            firstChildPositionForRow.add(position);
        }
    }

    private int getRowIndex(final int position) {
        return position < cells.size() ? cells.get(position).row : -1;
    }

    private int getSpannedRowCount() {
        return firstChildPositionForRow.size();
    }

    private int getNextSpannedRow(int rowIndex) {
        int firstPositionInRow = getFirstPositionInSpannedRow(rowIndex);
        int nextRow = rowIndex + 1;
        while (nextRow < getSpannedRowCount()
                && getFirstPositionInSpannedRow(nextRow) == firstPositionInRow) {
            nextRow++;
        }
        return nextRow;
    }

    private int getFirstPositionInSpannedRow(int rowIndex) {
        return firstChildPositionForRow.get(rowIndex);
    }

    private int getLastPositionInSpannedRow(final int rowIndex, RecyclerView.State state) {
        int nextRow = getNextSpannedRow(rowIndex);
        return (nextRow != getSpannedRowCount()) ? // check if reached boundary
                getFirstPositionInSpannedRow(nextRow) - 1
                : state.getItemCount() - 1;
    }

    /**
     * Lay out a given 'row'. We might actually add more that one row if the requested row contains
     * a row-spanning cell. Returns the pixel height of the rows laid out.
     * <p>
     * To simplify logic & book-keeping, views are attached in adapter order, that is child 0 will
     * always be the earliest position displayed etc.
     */
    private int layoutRow(
            int rowIndex, int startTop, RecyclerView.Recycler recycler, RecyclerView.State state) {
        int firstPositionInRow = getFirstPositionInSpannedRow(rowIndex);
        int lastPositionInRow = getLastPositionInSpannedRow(rowIndex, state);
        boolean containsRemovedItems = false;

        int insertPosition = (rowIndex < firstVisibleRow) ? 0 : getChildCount();
        for (int position = firstPositionInRow;
             position <= lastPositionInRow;
             position++, insertPosition++) {

            View view = recycler.getViewForPosition(position);
            LayoutParams lp = (LayoutParams) view.getLayoutParams();
            containsRemovedItems |= lp.isItemRemoved();
            GridCell cell = cells.get(position);
            addView(view, insertPosition);

            // TODO use orientation helper
            int wSpec = getChildMeasureSpec(
                    cellBorders[cell.column + cell.columnSpan] - cellBorders[cell.column],
                    View.MeasureSpec.EXACTLY, 0, lp.width, false);
            int hSpec = getChildMeasureSpec(cell.rowSpan * cellHeight,
                    View.MeasureSpec.EXACTLY, 0, lp.height, true);
            measureChildWithDecorationsAndMargin(view, wSpec, hSpec);

            int left = cellBorders[cell.column] + lp.leftMargin;
            int top = startTop + (cell.row * cellHeight) + lp.topMargin;
            int right = left + getDecoratedMeasuredWidth(view);
            int bottom = top + getDecoratedMeasuredHeight(view);
            layoutDecorated(view, left, top, right, bottom);
            lp.columnSpan = cell.columnSpan;
            lp.rowSpan = cell.rowSpan;
        }

        if (firstPositionInRow < firstVisiblePosition) {
            firstVisiblePosition = firstPositionInRow;
            firstVisibleRow = getRowIndex(firstVisiblePosition);
        }
        if (lastPositionInRow > lastVisiblePosition) {
            lastVisiblePosition = lastPositionInRow;
            lastVisibleRow = getRowIndex(lastVisiblePosition);
        }
        if (containsRemovedItems) return 0; // don't consume space for rows with disappearing items

        GridCell first = cells.get(firstPositionInRow);
        GridCell last = cells.get(lastPositionInRow);
        return (last.row + last.rowSpan - first.row) * cellHeight;
    }

    /**
     * Remove and recycle all items in this 'row'. If the row includes a row-spanning cell then all
     * cells in the spanned rows will be removed.
     */
    private void recycleRow(
            int rowIndex, RecyclerView.Recycler recycler, RecyclerView.State state) {
        int firstPositionInRow = getFirstPositionInSpannedRow(rowIndex);
        int lastPositionInRow = getLastPositionInSpannedRow(rowIndex, state);
        int toRemove = lastPositionInRow;
        while (toRemove >= firstPositionInRow) {
            int index = toRemove - firstVisiblePosition;
            removeAndRecycleViewAt(index, recycler);
            toRemove--;
        }
        if (rowIndex == firstVisibleRow) {
            firstVisiblePosition = lastPositionInRow + 1;
            firstVisibleRow = getRowIndex(firstVisiblePosition);
        }
        if (rowIndex == lastVisibleRow) {
            lastVisiblePosition = firstPositionInRow - 1;
            lastVisibleRow = getRowIndex(lastVisiblePosition);
        }
    }

    private void layoutDisappearingViews(
            RecyclerView.Recycler recycler, RecyclerView.State state, int startTop) {
        // TODO
    }

    private void calculateWindowSize() {
        // TODO use OrientationHelper#getTotalSpace
        int cellWidth =
                (int) Math.floor((getWidth() - getPaddingLeft() - getPaddingRight()) / columns);
        cellHeight = (int) Math.floor(cellWidth * (1f / cellAspectRatio));
        calculateCellBorders();
    }

    private void reset() {
        cells = null;
        firstChildPositionForRow = null;
        firstVisiblePosition = 0;
        firstVisibleRow = 0;
        lastVisiblePosition = 0;
        lastVisibleRow = 0;
        cellHeight = 0;
        forceClearOffsets = false;
    }

    private void resetVisibleItemTracking() {
        // maintain the firstVisibleRow but reset other state vars
        // TODO make orientation agnostic
        int minimumVisibleRow = getMinimumFirstVisibleRow();
        if (firstVisibleRow > minimumVisibleRow) firstVisibleRow = minimumVisibleRow;
        firstVisiblePosition = getFirstPositionInSpannedRow(firstVisibleRow);
        lastVisibleRow = firstVisibleRow;
        lastVisiblePosition = firstVisiblePosition;
    }

    private int getMinimumFirstVisibleRow() {
        int maxDisplayedRows = (int) Math.ceil((float) getHeight() / cellHeight) + 1;
        if (totalRows < maxDisplayedRows) return 0;
        int minFirstRow = totalRows - maxDisplayedRows;
        // adjust to spanned rows
        return getRowIndex(getFirstPositionInSpannedRow(minFirstRow));
    }

    /* Adapted from GridLayoutManager */

    private void calculateCellBorders() {
        cellBorders = new int[columns + 1];
        int totalSpace = getWidth() - getPaddingLeft() - getPaddingRight();
        int consumedPixels = getPaddingLeft();
        cellBorders[0] = consumedPixels;
        int sizePerSpan = totalSpace / columns;
        int sizePerSpanRemainder = totalSpace % columns;
        int additionalSize = 0;
        for (int i = 1; i <= columns; i++) {
            int itemSize = sizePerSpan;
            additionalSize += sizePerSpanRemainder;
            if (additionalSize > 0 && (columns - additionalSize) < sizePerSpanRemainder) {
                itemSize += 1;
                additionalSize -= columns;
            }
            consumedPixels += itemSize;
            cellBorders[i] = consumedPixels;
        }
    }

    private void measureChildWithDecorationsAndMargin(View child, int widthSpec, int heightSpec) {
        calculateItemDecorationsForChild(child, itemDecorationInsets);
        RecyclerView.LayoutParams lp = (RecyclerView.LayoutParams) child.getLayoutParams();
        widthSpec = updateSpecWithExtra(widthSpec, lp.leftMargin + itemDecorationInsets.left,
                lp.rightMargin + itemDecorationInsets.right);
        heightSpec = updateSpecWithExtra(heightSpec, lp.topMargin + itemDecorationInsets.top,
                lp.bottomMargin + itemDecorationInsets.bottom);
        child.measure(widthSpec, heightSpec);
    }

    private int updateSpecWithExtra(int spec, int startInset, int endInset) {
        if (startInset == 0 && endInset == 0) {
            return spec;
        }
        int mode = View.MeasureSpec.getMode(spec);
        if (mode == View.MeasureSpec.AT_MOST || mode == View.MeasureSpec.EXACTLY) {
            return View.MeasureSpec.makeMeasureSpec(
                    View.MeasureSpec.getSize(spec) - startInset - endInset, mode);
        }
        return spec;
    }

    /* Adapted from ConstraintLayout */

    private void parseAspectRatio(String aspect) {
        if (aspect != null) {
            int colonIndex = aspect.indexOf(':');
            if (colonIndex >= 0 && colonIndex < aspect.length() - 1) {
                String nominator = aspect.substring(0, colonIndex);
                String denominator = aspect.substring(colonIndex + 1);
                if (nominator.length() > 0 && denominator.length() > 0) {
                    try {
                        float nominatorValue = Float.parseFloat(nominator);
                        float denominatorValue = Float.parseFloat(denominator);
                        if (nominatorValue > 0 && denominatorValue > 0) {
                            cellAspectRatio = Math.abs(nominatorValue / denominatorValue);
                            return;
                        }
                    } catch (NumberFormatException e) {
                        // Ignore
                    }
                }
            }
        }
        throw new IllegalArgumentException("Could not parse aspect ratio: '" + aspect + "'");
    }

}

attrs.xml

<?xml version="1.0" encoding="utf-8"?> 
<resources>

    <declare-styleable name="SpannedGridLayoutManager">
        <attr name="android:orientation" />
        <attr name="spanCount" />
        <attr name="aspectRatio" format="string" />
    </declare-styleable>

</resources>

Le code est également disponible aquí .

Exemple d'utilisation

Le code nécessite RecyclerView 23.2.0 ou plus. Ajoutez donc la ligne suivante à votre build.gradle, si vous ne l'avez pas déjà fait.

dependencies {
    compile 'com.android.support:recyclerview-v7:24.2.1'
}

Pour réaliser la mise en page présentée dans le post initial, nous définissons le LayoutManager comme suit

recyclerView.setLayoutManager(new SpannedGridLayoutManager(
        new SpannedGridLayoutManager.GridSpanLookup() {
            @Override
            public SpannedGridLayoutManager.SpanInfo getSpanInfo(int position) {
                if (position == 0) {
                    return new SpannedGridLayoutManager.SpanInfo(2, 2);
                } else {
                    return new SpannedGridLayoutManager.SpanInfo(1, 1);
                }
            }
        }, 
        3 /* Three columns */, 
        1f /* We want our items to be 1:1 ratio */));

Answer 2

Vous pouvez utiliser la librairie SpannedGridLayoutManager écrite par Arasthel dans aquí

Voici le résultat

Answer 3

Vous pouvez obtenir ce comportement en utilisant RecycleView pour les lignes uniquement, avec ViewHolder pour chaque ligne. Vous aurez donc RowViewHolder pour les rangées simples et quelque chose comme DoubleRowViewHolder pour une mise en page personnalisée qui aura 3 éléments, exactement comme vous le souhaitez.