src/main/java/com/google/android/libraries/feed/piet/GridRowAdapter.java

// Copyright 2018 The Feed Authors.
//
// 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.

package com.google.android.libraries.feed.piet;

import static com.google.android.libraries.feed.common.Validators.checkState;
import static com.google.android.libraries.feed.piet.StyleProvider.DIMENSION_NOT_SET;
import static com.google.search.now.ui.piet.ErrorsProto.ErrorCode.ERR_GRID_CELL_WIDTH_WITHOUT_CONTENTS;
import static com.google.search.now.ui.piet.ErrorsProto.ErrorCode.ERR_MISSING_ELEMENT_CONTENTS;
import static com.google.search.now.ui.piet.ErrorsProto.ErrorCode.ERR_UNSUPPORTED_FEATURE;

import android.content.Context;
import android.support.annotation.VisibleForTesting;
import android.view.Gravity;
import android.view.View;
import android.widget.LinearLayout;
import com.google.android.libraries.feed.common.functional.Supplier;
import com.google.android.libraries.feed.common.ui.LayoutUtils;
import com.google.android.libraries.feed.piet.AdapterFactory.AdapterKeySupplier;
import com.google.android.libraries.feed.piet.AdapterFactory.SingletonKeySupplier;
import com.google.android.libraries.feed.piet.DebugLogger.MessageType;
import com.google.android.libraries.feed.piet.ui.GridRowView;
import com.google.android.libraries.feed.piet.ui.GridRowView.LayoutParams;
import com.google.search.now.ui.piet.ElementsProto.Content;
import com.google.search.now.ui.piet.ElementsProto.Element;
import com.google.search.now.ui.piet.ElementsProto.GridCell;
import com.google.search.now.ui.piet.ElementsProto.GridCellWidth;
import com.google.search.now.ui.piet.ElementsProto.GridCellWidth.WidthSpecCase;
import com.google.search.now.ui.piet.ElementsProto.GridRow;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/** An {@link ElementContainerAdapter} which manages {@code GridRow} slices. */
class GridRowAdapter extends ElementContainerAdapter<GridRowView, GridRow> {

  private static final String TAG = "GridRowAdapter";

  private GridRowAdapter(Context context, AdapterParameters parameters) {
    super(
        context,
        parameters,
        createView(context, parameters.hostProviders.getAssetProvider().isRtLSupplier()),
        KeySupplier.SINGLETON_KEY);
  }

  @Override
  GridRow getModelFromElement(Element baseElement) {
    if (!baseElement.hasGridRow()) {
      throw new PietFatalException(
          ERR_MISSING_ELEMENT_CONTENTS,
          String.format("Missing GridRow; has %s", baseElement.getElementsCase()));
    }
    return baseElement.getGridRow();
  }


  @Override
  List<Content> getContentsFromModel(GridRow model) {
    ArrayList<Content> contents = new ArrayList<>();
    for (GridCell cell : model.getCellsList()) {
      contents.add(cell.getContent());
    }
    contents.trimToSize();
    return Collections.unmodifiableList(contents);
  }

  @Override
  void onBindModel(GridRow gridRow, Element baseElement, FrameContext frameContext) {
    super.onBindModel(gridRow, baseElement, frameContext);

    int adapterIndex = 0;
    checkState(
        gridRow.getCellsCount() == adaptersPerContent.length,
        "Mismatch between number of cells (%s) and adaptersPerContent (%s); problem in creation?",
        gridRow.getCellsCount(),
        adaptersPerContent.length);
    for (int contentIndex = 0; contentIndex < gridRow.getCellsCount(); contentIndex++) {
      GridCell cell = gridRow.getCells(contentIndex);
      for (int i = 0; i < adaptersPerContent[contentIndex]; i++) {
        setLayoutParamsOnCell(childAdapters.get(adapterIndex), cell, frameContext);
        adapterIndex++;
      }
    }
  }

  @SuppressWarnings("UnnecessaryDefaultInEnumSwitch")
  private void setLayoutParamsOnCell(
      ElementAdapter<? extends View, ?> cellAdapter, GridCell cell, FrameContext frameContext) {
    // TODO: Support full-cell backgrounds and horizontal/vertical gravity for all
    // types of ElementAdapter in GridCell.

    GridCellWidth gridCellWidth = null;
    if (cell.hasWidth()) {
      gridCellWidth = cell.getWidth();
    } else if (cell.hasWidthBinding()) {
      gridCellWidth = frameContext.getGridCellWidthFromBinding(cell.getWidthBinding());
    }

    // Default cell is weight = 1 and height = WRAP_CONTENT.
    boolean isCollapsible =
        gridCellWidth != null
            && gridCellWidth.getWidthSpecCase() != WidthSpecCase.WEIGHT
            && gridCellWidth.getIsCollapsible();
    LayoutParams params;
    if (isCollapsible) {
      params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, 0.0f, true);
    } else {
      params = new LayoutParams(0, LayoutParams.WRAP_CONTENT, 1.0f, false);
    }

    // If a width is specified on the proto, we expect it to be populated so we can use it.
    if (gridCellWidth != null) {
      switch (gridCellWidth.getWidthSpecCase()) {
        case CONTENT_WIDTH:
          params.weight = 0;
          params.width = LayoutParams.WRAP_CONTENT;
          switch (gridCellWidth.getContentWidth()) {
            case CONTENT_WIDTH:
              if (cellAdapter.getComputedWidthPx() == LayoutParams.MATCH_PARENT) {
                frameContext.reportMessage(
                    MessageType.WARNING,
                    ERR_UNSUPPORTED_FEATURE,
                    "FIT_PARENT width is invalid for CONTENT_WIDTH cell contents.");
              } else if (cellAdapter.getComputedWidthPx() != DIMENSION_NOT_SET) {
                params.width = cellAdapter.getComputedWidthPx();
              }
              break;
            case INVALID_CONTENT_WIDTH:
            default:
              frameContext.reportMessage(
                  MessageType.WARNING,
                  ERR_GRID_CELL_WIDTH_WITHOUT_CONTENTS,
                  String.format(
                      "Invalid content width: %s", gridCellWidth.getContentWidth().name()));
          }
          break;
        case DP:
          params.weight = 0;
          params.width = (int) LayoutUtils.dpToPx(gridCellWidth.getDp(), getContext());
          break;
        case WEIGHT:
          params.weight = gridCellWidth.getWeight();
          params.width = 0;
          break;
        case WIDTHSPEC_NOT_SET:
        default:
          frameContext.reportMessage(
              MessageType.WARNING,
              ERR_GRID_CELL_WIDTH_WITHOUT_CONTENTS,
              String.format("Invalid content width: %s", gridCellWidth.getContentWidth().name()));
      }
    }

    params.height =
        cellAdapter.getComputedHeightPx() == DIMENSION_NOT_SET
            ? LayoutParams.MATCH_PARENT
            : cellAdapter.getComputedHeightPx();

    cellAdapter.getElementStyle().applyMargins(getContext(), params);

    params.gravity = cellAdapter.getVerticalGravity(Gravity.TOP);

    cellAdapter.setLayoutParams(params);
  }

  @VisibleForTesting
  static GridRowView createView(Context context, Supplier<Boolean> isRtL) {
    GridRowView viewGroup = new GridRowView(context, isRtL);
    viewGroup.setOrientation(LinearLayout.HORIZONTAL);
    viewGroup.setLayoutParams(
        new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
    viewGroup.setBaselineAligned(false);
    viewGroup.setClipToPadding(false);
    return viewGroup;
  }

  /** A {@link AdapterKeySupplier} for the {@link GridRowAdapter}. */
  static class KeySupplier extends SingletonKeySupplier<GridRowAdapter, GridRow> {
    @Override
    public String getAdapterTag() {
      return TAG;
    }

    @Override
    public GridRowAdapter getAdapter(Context context, AdapterParameters parameters) {
      return new GridRowAdapter(context, parameters);
    }
  }
}