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Diffstat (limited to 'app/src/main/java/fr/gouv/etalab/mastodon/helper/itemtouchhelper/SimpleItemTouchHelperCallback.java')
| -rw-r--r-- | app/src/main/java/fr/gouv/etalab/mastodon/helper/itemtouchhelper/SimpleItemTouchHelperCallback.java | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/app/src/main/java/fr/gouv/etalab/mastodon/helper/itemtouchhelper/SimpleItemTouchHelperCallback.java b/app/src/main/java/fr/gouv/etalab/mastodon/helper/itemtouchhelper/SimpleItemTouchHelperCallback.java new file mode 100644 index 000000000..480cf9bda --- /dev/null +++ b/app/src/main/java/fr/gouv/etalab/mastodon/helper/itemtouchhelper/SimpleItemTouchHelperCallback.java @@ -0,0 +1,126 @@ +package fr.gouv.etalab.mastodon.helper.itemtouchhelper; + +/* + * Copyright (C) 2015 Paul Burke + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + + +import android.graphics.Canvas; +import android.support.v7.widget.GridLayoutManager; +import android.support.v7.widget.RecyclerView; +import android.support.v7.widget.helper.ItemTouchHelper; + +import org.jetbrains.annotations.NotNull; + +/** + * An implementation of {@link ItemTouchHelper.Callback} that enables basic drag & drop and + * swipe-to-dismiss. Drag events are automatically started by an item long-press.<br/> + * </br/> + * Expects the <code>RecyclerView.Adapter</code> to listen for {@link + * ItemTouchHelperAdapter} callbacks and the <code>RecyclerView.ViewHolder</code> to implement + * {@link ItemTouchHelperViewHolder}. + * + * @author Paul Burke (ipaulpro) + */ +public class SimpleItemTouchHelperCallback extends ItemTouchHelper.Callback { + + private static final float ALPHA_FULL = 1.0f; + + private final ItemTouchHelperAdapter mAdapter; + + public SimpleItemTouchHelperCallback(ItemTouchHelperAdapter adapter) { + mAdapter = adapter; + } + + @Override + public boolean isLongPressDragEnabled() { + return true; + } + + @Override + public boolean isItemViewSwipeEnabled() { + return true; + } + + @Override + public int getMovementFlags(@NotNull RecyclerView recyclerView, @NotNull RecyclerView.ViewHolder viewHolder) { + // Set movement flags based on the layout manager + if (recyclerView.getLayoutManager() instanceof GridLayoutManager) { + final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT; + final int swipeFlags = 0; + return makeMovementFlags(dragFlags, swipeFlags); + } else { + final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN; + final int swipeFlags = ItemTouchHelper.START | ItemTouchHelper.END; + return makeMovementFlags(dragFlags, swipeFlags); + } + } + + @Override + public boolean onMove(@NotNull RecyclerView recyclerView, @NotNull RecyclerView.ViewHolder source, @NotNull RecyclerView.ViewHolder target) { + if (source.getItemViewType() != target.getItemViewType()) { + return false; + } + + // Notify the adapter of the move + mAdapter.onItemMove(source.getAdapterPosition(), target.getAdapterPosition()); + return true; + } + + @Override + public void onSwiped(@NotNull RecyclerView.ViewHolder viewHolder, int i) { + // Notify the adapter of the dismissal + mAdapter.onItemDismiss(viewHolder.getAdapterPosition()); + } + + @Override + public void onChildDraw(@NotNull Canvas c, @NotNull RecyclerView recyclerView, @NotNull RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) { + if (actionState == ItemTouchHelper.ACTION_STATE_SWIPE) { + // Fade out the view as it is swiped out of the parent's bounds + final float alpha = ALPHA_FULL - Math.abs(dX) / (float) viewHolder.itemView.getWidth(); + viewHolder.itemView.setAlpha(alpha); + viewHolder.itemView.setTranslationX(dX); + } else { + super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive); + } + } + + @Override + public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) { + // We only want the active item to change + if (actionState != ItemTouchHelper.ACTION_STATE_IDLE) { + if (viewHolder instanceof ItemTouchHelperViewHolder) { + // Let the view holder know that this item is being moved or dragged + ItemTouchHelperViewHolder itemViewHolder = (ItemTouchHelperViewHolder) viewHolder; + itemViewHolder.onItemSelected(); + } + } + + super.onSelectedChanged(viewHolder, actionState); + } + + @Override + public void clearView(@NotNull RecyclerView recyclerView, @NotNull RecyclerView.ViewHolder viewHolder) { + super.clearView(recyclerView, viewHolder); + + viewHolder.itemView.setAlpha(ALPHA_FULL); + + if (viewHolder instanceof ItemTouchHelperViewHolder) { + // Tell the view holder it's time to restore the idle state + ItemTouchHelperViewHolder itemViewHolder = (ItemTouchHelperViewHolder) viewHolder; + itemViewHolder.onItemClear(); + } + } +}
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