/*
* Copyright (C) 2010 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
*
* 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.android.internal.view.menu;
import android.content.Context;
import android.content.res.Configuration;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.View;
import android.view.ViewDebug;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityEvent;
import android.widget.LinearLayout;
/**
* @hide
*/
public class ActionMenuView extends LinearLayout implements MenuBuilder.ItemInvoker, MenuView {
private static final String TAG = "ActionMenuView";
static final int MIN_CELL_SIZE = 56; // dips
static final int GENERATED_ITEM_PADDING = 4; // dips
private MenuBuilder mMenu;
private boolean mReserveOverflow;
private ActionMenuPresenter mPresenter;
private boolean mFormatItems;
private int mFormatItemsWidth;
private int mMinCellSize;
private int mGeneratedItemPadding;
private int mMeasuredExtraWidth;
public ActionMenuView(Context context) {
this(context, null);
}
public ActionMenuView(Context context, AttributeSet attrs) {
super(context, attrs);
setBaselineAligned(false);
final float density = context.getResources().getDisplayMetrics().density;
mMinCellSize = (int) (MIN_CELL_SIZE * density);
mGeneratedItemPadding = (int) (GENERATED_ITEM_PADDING * density);
}
public void setPresenter(ActionMenuPresenter presenter) {
mPresenter = presenter;
}
public boolean isExpandedFormat() {
return mFormatItems;
}
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
mPresenter.updateMenuView(false);
if (mPresenter != null && mPresenter.isOverflowMenuShowing()) {
mPresenter.hideOverflowMenu();
mPresenter.showOverflowMenu();
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// If we've been given an exact size to match, apply special formatting during layout.
final boolean wasFormatted = mFormatItems;
mFormatItems = MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.EXACTLY;
if (wasFormatted != mFormatItems) {
mFormatItemsWidth = 0; // Reset this when switching modes
}
// Special formatting can change whether items can fit as action buttons.
// Kick the menu and update presenters when this changes.
final int widthSize = MeasureSpec.getMode(widthMeasureSpec);
if (mFormatItems && mMenu != null && widthSize != mFormatItemsWidth) {
mFormatItemsWidth = widthSize;
mMenu.onItemsChanged(true);
}
if (mFormatItems) {
onMeasureExactFormat(widthMeasureSpec, heightMeasureSpec);
} else {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
private void onMeasureExactFormat(int widthMeasureSpec, int heightMeasureSpec) {
// We already know the width mode is EXACTLY if we're here.
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
final int widthPadding = getPaddingLeft() + getPaddingRight();
final int heightPadding = getPaddingTop() + getPaddingBottom();
widthSize -= widthPadding;
// Divide the view into cells.
final int cellCount = widthSize / mMinCellSize;
final int cellSizeRemaining = widthSize % mMinCellSize;
if (cellCount == 0) {
// Give up, nothing fits.
setMeasuredDimension(widthSize, 0);
return;
}
final int cellSize = mMinCellSize + cellSizeRemaining / cellCount;
int cellsRemaining = cellCount;
int maxChildHeight = 0;
int maxCellsUsed = 0;
int expandableItemCount = 0;
int visibleItemCount = 0;
boolean hasOverflow = false;
// This is used as a bitfield to locate the smallest items present. Assumes childCount < 64.
long smallestItemsAt = 0;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = getChildAt(i);
if (child.getVisibility() == GONE) continue;
final boolean isGeneratedItem = child instanceof ActionMenuItemView;
visibleItemCount++;
if (isGeneratedItem) {
// Reset padding for generated menu item views; it may change below
// and views are recycled.
child.setPadding(mGeneratedItemPadding, 0, mGeneratedItemPadding, 0);
}
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
lp.expanded = false;
lp.extraPixels = 0;
lp.cellsUsed = 0;
lp.expandable = false;
lp.leftMargin = 0;
lp.rightMargin = 0;
lp.preventEdgeOffset = isGeneratedItem && ((ActionMenuItemView) child).hasText();
// Overflow always gets 1 cell. No more, no less.
final int cellsAvailable = lp.isOverflowButton ? 1 : cellsRemaining;
final int cellsUsed = measureChildForCells(child, cellSize, cellsAvailable,
heightMeasureSpec, heightPadding);
maxCellsUsed = Math.max(maxCellsUsed, cellsUsed);
if (lp.expandable) expandableItemCount++;
if (lp.isOverflowButton) hasOverflow = true;
cellsRemaining -= cellsUsed;
maxChildHeight = Math.max(maxChildHeight, child.getMeasuredHeight());
if (cellsUsed == 1) smallestItemsAt |= (1 << i);
}
// When we have overflow and a single expanded (text) item, we want to try centering it
// visually in the available space even though overflow consumes some of it.
final boolean centerSingleExpandedItem = hasOverflow && visibleItemCount == 2;
// Divide space for remaining cells if we have items that can expand.
// Try distributing whole leftover cells to smaller items first.
boolean needsExpansion = false;
while (expandableItemCount > 0 && cellsRemaining > 0) {
int minCells = Integer.MAX_VALUE;
long minCellsAt = 0; // Bit locations are indices of relevant child views
int minCellsItemCount = 0;
for (int i = 0; i < childCount; i++) {
final View child = getChildAt(i);
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
// Don't try to expand items that shouldn't.
if (!lp.expandable) continue;
// Mark indices of children that can receive an extra cell.
if (lp.cellsUsed < minCells) {
minCells = lp.cellsUsed;
minCellsAt = 1 << i;
minCellsItemCount = 1;
} else if (lp.cellsUsed == minCells) {
minCellsAt |= 1 << i;
minCellsItemCount++;
}
}
// Items that get expanded will always be in the set of smallest items when we're done.
smallestItemsAt |= minCellsAt;
if (minCellsItemCount > cellsRemaining) break; // Couldn't expand anything evenly. Stop.
// We have enough cells, all minimum size items will be incremented.
minCells++;
for (int i = 0; i < childCount; i++) {
final View child = getChildAt(i);
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
if ((minCellsAt & (1 << i)) == 0) {
// If this item is already at our small item count, mark it for later.
if (lp.cellsUsed == minCells) smallestItemsAt |= 1 << i;
continue;
}
if (centerSingleExpandedItem && lp.preventEdgeOffset && cellsRemaining == 1) {
// Add padding to this item such that it centers.
child.setPadding(mGeneratedItemPadding + cellSize, 0, mGeneratedItemPadding, 0);
}
lp.cellsUsed++;
lp.expanded = true;
cellsRemaining--;
}
needsExpansion = true;
}
// Divide any space left that wouldn't divide along cell boundaries
// evenly among the smallest items
final boolean singleItem = !hasOverflow && visibleItemCount == 1;
if (cellsRemaining > 0 && smallestItemsAt != 0 &&
(cellsRemaining < visibleItemCount - 1 || singleItem || maxCellsUsed > 1)) {
float expandCount = Long.bitCount(smallestItemsAt);
if (!singleItem) {
// The items at the far edges may only expand by half in order to pin to either side.
if ((smallestItemsAt & 1) != 0) {
LayoutParams lp = (LayoutParams) getChildAt(0).getLayoutParams();
if (!lp.preventEdgeOffset) expandCount -= 0.5f;
}
if ((smallestItemsAt & (1 << (childCount - 1))) != 0) {
LayoutParams lp = ((LayoutParams) getChildAt(childCount - 1).getLayoutParams());
if (!lp.preventEdgeOffset) expandCount -= 0.5f;
}
}
final int extraPixels = expandCount > 0 ?
(int) (cellsRemaining * cellSize / expandCount) : 0;
for (int i = 0; i < childCount; i++) {
if ((smallestItemsAt & (1 << i)) == 0) continue;
final View child = getChildAt(i);
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (child instanceof ActionMenuItemView) {
// If this is one of our views, expand and measure at the larger size.
lp.extraPixels = extraPixels;
lp.expanded = true;
if (i == 0 && !lp.preventEdgeOffset) {
// First item gets part of its new padding pushed out of sight.
// The last item will get this implicitly from layout.
lp.leftMargin = -extraPixels / 2;
}
needsExpansion = true;
} else if (lp.isOverflowButton) {
lp.extraPixels = extraPixels;
lp.expanded = true;
lp.rightMargin = -extraPixels / 2;
needsExpansion = true;
} else {
// If we don't know what it is, give it some margins instead
// and let it center within its space. We still want to pin
// against the edges.
if (i != 0) {
lp.leftMargin = extraPixels / 2;
}
if (i != childCount - 1) {
lp.rightMargin = extraPixels / 2;
}
}
}
cellsRemaining = 0;
}
// Remeasure any items that have had extra space allocated to them.
if (needsExpansion) {
int heightSpec = MeasureSpec.makeMeasureSpec(heightSize - heightPadding, heightMode);
for (int i = 0; i < childCount; i++) {
final View child = getChildAt(i);
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (!lp.expanded) continue;
final int width = lp.cellsUsed * cellSize + lp.extraPixels;
child.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY), heightSpec);
}
}
if (heightMode != MeasureSpec.EXACTLY) {
heightSize = maxChildHeight;
}
setMeasuredDimension(widthSize, heightSize);
mMeasuredExtraWidth = cellsRemaining * cellSize;
}
/**
* Measure a child view to fit within cell-based formatting. The child's width
* will be measured to a whole multiple of cellSize.
*
* <p>Sets the expandable and cellsUsed fields of LayoutParams.
*
* @param child Child to measure
* @param cellSize Size of one cell
* @param cellsRemaining Number of cells remaining that this view can expand to fill
* @param parentHeightMeasureSpec MeasureSpec used by the parent view
* @param parentHeightPadding Padding present in the parent view
* @return Number of cells this child was measured to occupy
*/
static int measureChildForCells(View child, int cellSize, int cellsRemaining,
int parentHeightMeasureSpec, int parentHeightPadding) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final int childHeightSize = MeasureSpec.getSize(parentHeightMeasureSpec) -
parentHeightPadding;
final int childHeightMode = MeasureSpec.getMode(parentHeightMeasureSpec);
final int childHeightSpec = MeasureSpec.makeMeasureSpec(childHeightSize, childHeightMode);
int cellsUsed = 0;
if (cellsRemaining > 0) {
final int childWidthSpec = MeasureSpec.makeMeasureSpec(
cellSize * cellsRemaining, MeasureSpec.AT_MOST);
child.measure(childWidthSpec, childHeightSpec);
final int measuredWidth = child.getMeasuredWidth();
cellsUsed = measuredWidth / cellSize;
if (measuredWidth % cellSize != 0) cellsUsed++;
}
final ActionMenuItemView itemView = child instanceof ActionMenuItemView ?
(ActionMenuItemView) child : null;
final boolean expandable = !lp.isOverflowButton && itemView != null && itemView.hasText();
lp.expandable = expandable;
lp.cellsUsed = cellsUsed;
final int targetWidth = cellsUsed * cellSize;
child.measure(MeasureSpec.makeMeasureSpec(targetWidth, MeasureSpec.EXACTLY),
childHeightSpec);
return cellsUsed;
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
if (!mFormatItems) {
super.onLayout(changed, left, top, right, bottom);
return;
}
final int childCount = getChildCount();
final int midVertical = (top + bottom) / 2;
final int dividerWidth = getDividerWidth();
int overflowWidth = 0;
int nonOverflowWidth = 0;
int nonOverflowCount = 0;
int widthRemaining = right - left - getPaddingRight() - getPaddingLeft();
boolean hasOverflow = false;
for (int i = 0; i < childCount; i++) {
final View v = getChildAt(i);
if (v.getVisibility() == GONE) {
continue;
}
LayoutParams p = (LayoutParams) v.getLayoutParams();
if (p.isOverflowButton) {
overflowWidth = v.getMeasuredWidth();
if (hasDividerBeforeChildAt(i)) {
overflowWidth += dividerWidth;
}
int height = v.getMeasuredHeight();
int r = getWidth() - getPaddingRight() - p.rightMargin;
int l = r - overflowWidth;
int t = midVertical - (height / 2);
int b = t + height;
v.layout(l, t, r, b);
widthRemaining -= overflowWidth;
hasOverflow = true;
} else {
final int size = v.getMeasuredWidth() + p.leftMargin + p.rightMargin;
nonOverflowWidth += size;
widthRemaining -= size;
if (hasDividerBeforeChildAt(i)) {
nonOverflowWidth += dividerWidth;
}
nonOverflowCount++;
}
}
if (childCount == 1 && !hasOverflow) {
// Center a single child
final View v = getChildAt(0);
final int width = v.getMeasuredWidth();
final int height = v.getMeasuredHeight();
final int midHorizontal = (right - left) / 2;
final int l = midHorizontal - width / 2;
final int t = midVertical - height / 2;
v.layout(l, t, l + width, t + height);
return;
}
final int spacerCount = nonOverflowCount - (hasOverflow ? 0 : 1);
final int spacerSize = Math.max(0, spacerCount > 0 ? widthRemaining / spacerCount : 0);
int startLeft = getPaddingLeft();
for (int i = 0; i < childCount; i++) {
final View v = getChildAt(i);
final LayoutParams lp = (LayoutParams) v.getLayoutParams();
if (v.getVisibility() == GONE || lp.isOverflowButton) {
continue;
}
startLeft += lp.leftMargin;
int width = v.getMeasuredWidth();
int height = v.getMeasuredHeight();
int t = midVertical - height / 2;
v.layout(startLeft, t, startLeft + width, t + height);
startLeft += width + lp.rightMargin + spacerSize;
}
}
@Override
public void onDetachedFromWindow() {
super.onDetachedFromWindow();
mPresenter.dismissPopupMenus();
}
public boolean isOverflowReserved() {
return mReserveOverflow;
}
public void setOverflowReserved(boolean reserveOverflow) {
mReserveOverflow = reserveOverflow;
}
@Override
protected LayoutParams generateDefaultLayoutParams() {
LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
params.gravity = Gravity.CENTER_VERTICAL;
return params;
}
@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
return new LayoutParams(getContext(), attrs);
}
@Override
protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
if (p instanceof LayoutParams) {
LayoutParams result = new LayoutParams((LayoutParams) p);
if (result.gravity <= Gravity.NO_GRAVITY) {
result.gravity = Gravity.CENTER_VERTICAL;
}
return result;
}
return generateDefaultLayoutParams();
}
@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
return p != null && p instanceof LayoutParams;
}
public LayoutParams generateOverflowButtonLayoutParams() {
LayoutParams result = generateDefaultLayoutParams();
result.isOverflowButton = true;
return result;
}
public boolean invokeItem(MenuItemImpl item) {
return mMenu.performItemAction(item, 0);
}
public int getWindowAnimations() {
return 0;
}
public void initialize(MenuBuilder menu) {
mMenu = menu;
}
@Override
protected boolean hasDividerBeforeChildAt(int childIndex) {
final View childBefore = getChildAt(childIndex - 1);
final View child = getChildAt(childIndex);
boolean result = false;
if (childIndex < getChildCount() && childBefore instanceof ActionMenuChildView) {
result |= ((ActionMenuChildView) childBefore).needsDividerAfter();
}
if (childIndex > 0 && child instanceof ActionMenuChildView) {
result |= ((ActionMenuChildView) child).needsDividerBefore();
}
return result;
}
public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) {
return false;
}
public interface ActionMenuChildView {
public boolean needsDividerBefore();
public boolean needsDividerAfter();
}
public static class LayoutParams extends LinearLayout.LayoutParams {
@ViewDebug.ExportedProperty(category = "layout")
public boolean isOverflowButton;
@ViewDebug.ExportedProperty(category = "layout")
public int cellsUsed;
@ViewDebug.ExportedProperty(category = "layout")
public int extraPixels;
@ViewDebug.ExportedProperty(category = "layout")
public boolean expandable;
@ViewDebug.ExportedProperty(category = "layout")
public boolean preventEdgeOffset;
public boolean expanded;
public LayoutParams(Context c, AttributeSet attrs) {
super(c, attrs);
}
public LayoutParams(LayoutParams other) {
super((LinearLayout.LayoutParams) other);
isOverflowButton = other.isOverflowButton;
}
public LayoutParams(int width, int height) {
super(width, height);
isOverflowButton = false;
}
public LayoutParams(int width, int height, boolean isOverflowButton) {
super(width, height);
this.isOverflowButton = isOverflowButton;
}
}
}