ChipGroup.java

/*
 * Copyright 2017 The Android Open Source Project
 *
 * 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
 *
 *     https://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.material.chip;

import com.google.android.material.R;

import static com.google.android.material.theme.overlay.MaterialThemeOverlay.wrap;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityNodeInfo;
import androidx.annotation.BoolRes;
import androidx.annotation.DimenRes;
import androidx.annotation.Dimension;
import androidx.annotation.IdRes;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.core.view.accessibility.AccessibilityNodeInfoCompat;
import androidx.core.view.accessibility.AccessibilityNodeInfoCompat.CollectionInfoCompat;
import com.google.android.material.internal.CheckableGroup;
import com.google.android.material.internal.FlowLayout;
import com.google.android.material.internal.ThemeEnforcement;
import java.util.List;
import java.util.Set;

/**
 * A ChipGroup is used to hold multiple {@link Chip}s. By default, the chips are reflowed across
 * multiple lines. Set the {@code app:singleLine} attribute to constrain the chips to a single
 * horizontal line. If you do so, you'll usually want to wrap this ChipGroup in a {@link
 * android.widget.HorizontalScrollView}.
 *
 * <p>ChipGroup also supports a multiple-exclusion scope for a set of chips. When you set the {@code
 * app:singleSelection} attribute, checking one chip that belongs to a chip group unchecks any
 * previously checked chip within the same group. The behavior mirrors that of {@link
 * android.widget.RadioGroup}.
 *
 * <p>When a chip is added to a chip group, its checked state will be preserved. If the chip group
 * is in the single selection mode and there is an existing checked chip when another checked chip
 * is added, the existing checked chip will be unchecked to maintain the single selection rule.
 *
 * <p>For more information, see the <a
 * href="https://github.com/material-components/material-components-android/blob/master/docs/components/Chip.md">component
 * developer guidance</a> and <a href="https://material.io/components/chips/overview">design
 * guidelines</a>.
 */
public class ChipGroup extends FlowLayout {

  /**
   * Interface definition for a callback to be invoked when the checked chip changed in this group.
   *
   * @deprecated Use {@link OnCheckedStateChangeListener} instead.
   */
  @Deprecated
  public interface OnCheckedChangeListener {
    /**
     * Called when the checked chip has changed. When the selection is cleared, checkedId is {@link
     * View#NO_ID}.
     *
     * @param group the group in which the checked chip has changed
     * @param checkedId the unique identifier of the newly checked chip
     */
    void onCheckedChanged(@NonNull ChipGroup group, @IdRes int checkedId);
  }

  /**
   * Interface definition for a callback which supports multiple checked IDs to be invoked when the
   * checked chips changed in this group.
   */
  public interface OnCheckedStateChangeListener {
    /**
     * Called when the checked chips are changed. When the selection is cleared, {@code checkedIds}
     * will be an empty list.
     *
     * @param group the group in which the checked chip has changed
     * @param checkedIds the unique identifier list of the newly checked chips
     */
    void onCheckedChanged(@NonNull ChipGroup group, @NonNull List<Integer> checkedIds);
  }

  /** A {@link ChipGroup.LayoutParams} implementation for {@link ChipGroup}. */
  public static class LayoutParams extends MarginLayoutParams {
    public LayoutParams(Context context, AttributeSet attrs) {
      super(context, attrs);
    }

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

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

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

  private static final int DEF_STYLE_RES = R.style.Widget_MaterialComponents_ChipGroup;

  @Dimension private int chipSpacingHorizontal;
  @Dimension private int chipSpacingVertical;

  @Nullable private OnCheckedStateChangeListener onCheckedStateChangeListener;

  private final CheckableGroup<Chip> checkableGroup = new CheckableGroup<>();
  private final int defaultCheckedId;

  @NonNull
  private final PassThroughHierarchyChangeListener passThroughListener =
      new PassThroughHierarchyChangeListener();

  public ChipGroup(Context context) {
    this(context, null);
  }

  public ChipGroup(Context context, AttributeSet attrs) {
    this(context, attrs, R.attr.chipGroupStyle);
  }

  public ChipGroup(Context context, AttributeSet attrs, int defStyleAttr) {
    super(wrap(context, attrs, defStyleAttr, DEF_STYLE_RES), attrs, defStyleAttr);
    // Ensure we are using the correctly themed context rather than the context that was passed in.
    context = getContext();

    TypedArray a =
        ThemeEnforcement.obtainStyledAttributes(
            context, attrs, R.styleable.ChipGroup, defStyleAttr, DEF_STYLE_RES);

    int chipSpacing = a.getDimensionPixelOffset(R.styleable.ChipGroup_chipSpacing, 0);
    setChipSpacingHorizontal(
        a.getDimensionPixelOffset(R.styleable.ChipGroup_chipSpacingHorizontal, chipSpacing));
    setChipSpacingVertical(
        a.getDimensionPixelOffset(R.styleable.ChipGroup_chipSpacingVertical, chipSpacing));
    setSingleLine(a.getBoolean(R.styleable.ChipGroup_singleLine, false));
    setSingleSelection(a.getBoolean(R.styleable.ChipGroup_singleSelection, false));
    setSelectionRequired(a.getBoolean(R.styleable.ChipGroup_selectionRequired, false));
    defaultCheckedId = a.getResourceId(R.styleable.ChipGroup_checkedChip, View.NO_ID);

    a.recycle();

    checkableGroup.setOnCheckedStateChangeListener(
        new CheckableGroup.OnCheckedStateChangeListener() {
          @Override
          public void onCheckedStateChanged(Set<Integer> checkedIds) {
            if (onCheckedStateChangeListener != null) {
              onCheckedStateChangeListener.onCheckedChanged(
                  ChipGroup.this,
                  checkableGroup.getCheckedIdsSortedByChildOrder(ChipGroup.this));
            }
          }
        });
    super.setOnHierarchyChangeListener(passThroughListener);

    setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
  }

  @Override
  public void onInitializeAccessibilityNodeInfo(@NonNull AccessibilityNodeInfo info) {
    super.onInitializeAccessibilityNodeInfo(info);
    AccessibilityNodeInfoCompat infoCompat = AccessibilityNodeInfoCompat.wrap(info);
    // -1 for an unknown number of columns in a reflowing layout
    int columnCount = isSingleLine() ? getVisibleChipCount() : -1;
    infoCompat.setCollectionInfo(
        CollectionInfoCompat.obtain(
            /* rowCount= */ getRowCount(),
            /* columnCount= */ columnCount,
            /* hierarchical= */ false,
            /* selectionMode = */ isSingleSelection()
                ? CollectionInfoCompat.SELECTION_MODE_SINGLE
                : CollectionInfoCompat.SELECTION_MODE_MULTIPLE));
  }

  @NonNull
  @Override
  public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) {
    return new ChipGroup.LayoutParams(getContext(), attrs);
  }

  @NonNull
  @Override
  protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) {
    return new ChipGroup.LayoutParams(lp);
  }

  @NonNull
  @Override
  protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
    return new ChipGroup.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
  }

  @Override
  protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
    return super.checkLayoutParams(p) && (p instanceof ChipGroup.LayoutParams);
  }

  @Override
  public void setOnHierarchyChangeListener(OnHierarchyChangeListener listener) {
    // the user listener is delegated to our pass-through listener
    passThroughListener.onHierarchyChangeListener = listener;
  }

  @Override
  protected void onFinishInflate() {
    super.onFinishInflate();

    // checks the appropriate chip as requested in the XML file
    if (defaultCheckedId != View.NO_ID) {
      checkableGroup.check(defaultCheckedId);
    }
  }

  /** @deprecated Use {@link ChipGroup#setChipSpacingHorizontal(int)} instead. */
  @Deprecated
  public void setDividerDrawableHorizontal(Drawable divider) {
    throw new UnsupportedOperationException(
        "Changing divider drawables have no effect. ChipGroup do not use divider drawables as "
            + "spacing.");
  }

  /** @deprecated Use {@link ChipGroup#setChipSpacingVertical(int)} instead. */
  @Deprecated
  public void setDividerDrawableVertical(@Nullable Drawable divider) {
    throw new UnsupportedOperationException(
        "Changing divider drawables have no effect. ChipGroup do not use divider drawables as "
            + "spacing.");
  }

  /** @deprecated Use {@link ChipGroup#setChipSpacingHorizontal(int)} instead. */
  @Deprecated
  public void setShowDividerHorizontal(int dividerMode) {
    throw new UnsupportedOperationException(
        "Changing divider modes has no effect. ChipGroup do not use divider drawables as spacing.");
  }

  /** @deprecated Use {@link ChipGroup#setChipSpacingVertical(int)} instead. */
  @Deprecated
  public void setShowDividerVertical(int dividerMode) {
    throw new UnsupportedOperationException(
        "Changing divider modes has no effect. ChipGroup do not use divider drawables as spacing.");
  }

  /** @deprecated Use {@link ChipGroup#setSingleLine(int)} instead. */
  @Deprecated
  public void setFlexWrap(int flexWrap) {
    throw new UnsupportedOperationException(
        "Changing flex wrap not allowed. ChipGroup exposes a singleLine attribute instead.");
  }

  /**
   * Sets the selection to the chip whose identifier is passed in parameter.
   *
   * <p>In {@link #isSingleSelection() single selection mode}, checking a chip also unchecks all
   * others.
   *
   * @param id the unique id of the chip to select in this group
   * @see #getCheckedChipId()
   * @see #clearCheck()
   */
  public void check(@IdRes int id) {
    checkableGroup.check(id);
  }
  /**
   * When in {@link #isSingleSelection() single selection mode}, returns the identifier of the
   * selected chip in this group. Upon empty selection, the returned value is {@link View#NO_ID}. If
   * not in single selection mode, the return value is {@link View#NO_ID}.
   *
   * @return the unique id of the selected chip in this group in single selection mode
   * @see #check(int)
   * @see #clearCheck()
   * @see #getCheckedChipIds()
   * @attr ref R.styleable#ChipGroup_checkedChip
   */
  @IdRes
  public int getCheckedChipId() {
    return checkableGroup.getSingleCheckedId();
  }

  /**
   * Returns the identifiers of the selected {@link Chip}s in this group. Upon empty selection, the
   * returned value is an empty list.
   *
   * @return The unique IDs of the selected {@link Chip}s in this group. When in {@link
   *     #isSingleSelection() single selection mode}, returns a list with a single ID. When no
   *     {@link Chip}s are selected, returns an empty list.
   * @see #check(int)
   * @see #clearCheck()
   * @see #getCheckedChipId()
   */
  @NonNull
  public List<Integer> getCheckedChipIds() {
    return checkableGroup.getCheckedIdsSortedByChildOrder(this);
  }

  /**
   * Clears the selection. When the selection is cleared, no chip in this group is selected and
   * {@link #getCheckedChipId()} returns {@link View#NO_ID}.
   *
   * @see #check(int)
   * @see #getCheckedChipId()
   * @see #getCheckedChipIds()
   */
  public void clearCheck() {
    checkableGroup.clearCheck();
  }

  /**
   * Register a callback to be invoked when the checked chip changes in this group. This callback is
   * only invoked in {@link #isSingleSelection() single selection mode}.
   *
   * @param listener the callback to call on checked state change
   * @deprecated use {@link #setOnCheckedStateChangeListener(OnCheckedStateChangeListener)} instead.
   */
  @Deprecated
  public void setOnCheckedChangeListener(@Nullable final OnCheckedChangeListener listener) {
    if (listener == null) {
      setOnCheckedStateChangeListener(null);
      return;
    }
    setOnCheckedStateChangeListener(
        new OnCheckedStateChangeListener() {
          @Override
          public void onCheckedChanged(
              @NonNull ChipGroup group, @NonNull List<Integer> checkedIds) {
            if (!checkableGroup.isSingleSelection()) {
              return;
            }
            listener.onCheckedChanged(group, getCheckedChipId());
          }
        });
  }

  /**
   * Register a callback to be invoked when the checked chip changes in this group. This callback is
   * only invoked in {@link #isSingleSelection() single selection mode}.
   *
   * @param listener the callback to call on checked state change
   */
  public void setOnCheckedStateChangeListener(@Nullable OnCheckedStateChangeListener listener) {
    onCheckedStateChangeListener = listener;
  }

  private int getVisibleChipCount() {
    int count = 0;
    for (int i = 0; i < getChildCount(); i++) {
      if (getChildAt(i) instanceof Chip && isChildVisible(i)) {
        count++;
      }
    }
    return count;
  }

  /**
   * Returns the index of the Chip within the Chip children.
   *
   * <p>Non-Chip and non-visible children are ignored when computing the index.
   */
  int getIndexOfChip(@Nullable View child) {
    if (!(child instanceof Chip)) {
      return -1;
    }
    int index = 0;
    for (int i = 0; i < getChildCount(); i++) {
      View current = getChildAt(i);
      if (current instanceof Chip && isChildVisible(i)) {
        Chip chip = (Chip) current;
        if (chip == child) {
          return index;
        }
        index++;
      }
    }
    return -1;
  }

  private boolean isChildVisible(int i) {
    return getChildAt(i).getVisibility() == VISIBLE;
  }

  /** Sets the horizontal and vertical spacing between visible chips in this group. */
  public void setChipSpacing(@Dimension int chipSpacing) {
    setChipSpacingHorizontal(chipSpacing);
    setChipSpacingVertical(chipSpacing);
  }

  /** Sets the horizontal and vertical spacing between visible chips in this group. */
  public void setChipSpacingResource(@DimenRes int id) {
    setChipSpacing(getResources().getDimensionPixelOffset(id));
  }

  /** Returns the horizontal spacing between visible chips in this group. */
  @Dimension
  public int getChipSpacingHorizontal() {
    return chipSpacingHorizontal;
  }

  /** Sets the horizontal spacing between visible chips in this group. */
  public void setChipSpacingHorizontal(@Dimension int chipSpacingHorizontal) {
    if (this.chipSpacingHorizontal != chipSpacingHorizontal) {
      this.chipSpacingHorizontal = chipSpacingHorizontal;
      setItemSpacing(chipSpacingHorizontal);
      requestLayout();
    }
  }

  /** Sets the horizontal spacing between visible chips in this group. */
  public void setChipSpacingHorizontalResource(@DimenRes int id) {
    setChipSpacingHorizontal(getResources().getDimensionPixelOffset(id));
  }

  /** Returns the vertical spacing between visible chips in this group. */
  @Dimension
  public int getChipSpacingVertical() {
    return chipSpacingVertical;
  }

  /** Sets the vertical spacing between visible chips in this group. */
  public void setChipSpacingVertical(@Dimension int chipSpacingVertical) {
    if (this.chipSpacingVertical != chipSpacingVertical) {
      this.chipSpacingVertical = chipSpacingVertical;
      setLineSpacing(chipSpacingVertical);
      requestLayout();
    }
  }

  /** Sets the vertical spacing between visible chips in this group. */
  public void setChipSpacingVerticalResource(@DimenRes int id) {
    setChipSpacingVertical(getResources().getDimensionPixelOffset(id));
  }

  // Need to override here in order to un-restrict access to this method outside of the library.
  @SuppressWarnings("RedundantOverride")
  @Override
  public boolean isSingleLine() {
    return super.isSingleLine();
  }

  // Need to override here in order to un-restrict access to this method outside of the library.
  @SuppressWarnings("RedundantOverride")
  @Override
  public void setSingleLine(boolean singleLine) {
    super.setSingleLine(singleLine);
  }

  /** Sets whether this chip group is single line, or reflowed multiline. */
  public void setSingleLine(@BoolRes int id) {
    setSingleLine(getResources().getBoolean(id));
  }

  /** Returns whether this chip group only allows a single chip to be checked. */
  public boolean isSingleSelection() {
    return checkableGroup.isSingleSelection();
  }

  /**
   * Sets whether this chip group only allows a single chip to be checked.
   *
   * <p>Calling this method results in all the chips in this group to become unchecked.
   */
  public void setSingleSelection(boolean singleSelection) {
    checkableGroup.setSingleSelection(singleSelection);
  }

  /**
   * Sets whether this chip group only allows a single chip to be checked.
   *
   * <p>Calling this method results in all the chips in this group to become unchecked.
   */
  public void setSingleSelection(@BoolRes int id) {
    setSingleSelection(getResources().getBoolean(id));
  }

  /**
   * Sets whether we prevent all child chips from being deselected.
   *
   * @attr ref R.styleable#ChipGroup_selectionRequired
   * @see #setSingleSelection(boolean)
   */
  public void setSelectionRequired(boolean selectionRequired) {
    checkableGroup.setSelectionRequired(selectionRequired);
  }

  /**
   * Returns whether we prevent all child chips from being deselected.
   *
   * @attr ref R.styleable#ChipGroup_selectionRequired
   * @see #setSingleSelection(boolean)
   * @see #setSelectionRequired(boolean)
   */
  public boolean isSelectionRequired() {
    return checkableGroup.isSelectionRequired();
  }

  /**
   * A pass-through listener acts upon the events and dispatches them to another listener. This
   * allows the layout to set its own internal hierarchy change listener without preventing the user
   * to setup theirs.
   */
  private class PassThroughHierarchyChangeListener implements OnHierarchyChangeListener {
    private OnHierarchyChangeListener onHierarchyChangeListener;

    @Override
    public void onChildViewAdded(View parent, View child) {
      if (parent == ChipGroup.this && child instanceof Chip) {
        int id = child.getId();
        // generates an id if it's missing
        if (id == View.NO_ID) {
          id = View.generateViewId();
          child.setId(id);
        }
        checkableGroup.addCheckable((Chip) child);
      }

      if (onHierarchyChangeListener != null) {
        onHierarchyChangeListener.onChildViewAdded(parent, child);
      }
    }

    @Override
    public void onChildViewRemoved(View parent, View child) {
      if (parent == ChipGroup.this && child instanceof Chip) {
        checkableGroup.removeCheckable((Chip) child);
      }

      if (onHierarchyChangeListener != null) {
        onHierarchyChangeListener.onChildViewRemoved(parent, child);
      }
    }
  }
}