/*
* Copyright (C) 2007 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 android.widget;
import com.android.internal.R;
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.util.SparseBooleanArray;
import android.view.View;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import java.util.regex.Pattern;
/**
* <p>A layout that arranges its children into rows and columns.
* A TableLayout consists of a number of {@link android.widget.TableRow} objects,
* each defining a row (actually, you can have other children, which will be
* explained below). TableLayout containers do not display border lines for
* their rows, columns, or cells. Each row has zero or more cells; each cell can
* hold one {@link android.view.View View} object. The table has as many columns
* as the row with the most cells. A table can leave cells empty. Cells can span
* columns, as they can in HTML.</p>
*
* <p>The width of a column is defined by the row with the widest cell in that
* column. However, a TableLayout can specify certain columns as shrinkable or
* stretchable by calling
* {@link #setColumnShrinkable(int, boolean) setColumnShrinkable()}
* or {@link #setColumnStretchable(int, boolean) setColumnStretchable()}. If
* marked as shrinkable, the column width can be shrunk to fit the table into
* its parent object. If marked as stretchable, it can expand in width to fit
* any extra space. The total width of the table is defined by its parent
* container. It is important to remember that a column can be both shrinkable
* and stretchable. In such a situation, the column will change its size to
* always use up the available space, but never more. Finally, you can hide a
* column by calling
* {@link #setColumnCollapsed(int,boolean) setColumnCollapsed()}.</p>
*
* <p>The children of a TableLayout cannot specify the <code>layout_width</code>
* attribute. Width is always <code>MATCH_PARENT</code>. However, the
* <code>layout_height</code> attribute can be defined by a child; default value
* is {@link android.widget.TableLayout.LayoutParams#WRAP_CONTENT}. If the child
* is a {@link android.widget.TableRow}, then the height is always
* {@link android.widget.TableLayout.LayoutParams#WRAP_CONTENT}.</p>
*
* <p> Cells must be added to a row in increasing column order, both in code and
* XML. Column numbers are zero-based. If you don't specify a column number for
* a child cell, it will autoincrement to the next available column. If you skip
* a column number, it will be considered an empty cell in that row. See the
* TableLayout examples in ApiDemos for examples of creating tables in XML.</p>
*
* <p>Although the typical child of a TableLayout is a TableRow, you can
* actually use any View subclass as a direct child of TableLayout. The View
* will be displayed as a single row that spans all the table columns.</p>
*
*/
public class TableLayout extends LinearLayout {
private int[] mMaxWidths;
private SparseBooleanArray mStretchableColumns;
private SparseBooleanArray mShrinkableColumns;
private SparseBooleanArray mCollapsedColumns;
private boolean mShrinkAllColumns;
private boolean mStretchAllColumns;
private TableLayout.PassThroughHierarchyChangeListener mPassThroughListener;
private boolean mInitialized;
/**
* <p>Creates a new TableLayout for the given context.</p>
*
* @param context the application environment
*/
public TableLayout(Context context) {
super(context);
initTableLayout();
}
/**
* <p>Creates a new TableLayout for the given context and with the
* specified set attributes.</p>
*
* @param context the application environment
* @param attrs a collection of attributes
*/
public TableLayout(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.TableLayout);
String stretchedColumns = a.getString(R.styleable.TableLayout_stretchColumns);
if (stretchedColumns != null) {
if (stretchedColumns.charAt(0) == '*') {
mStretchAllColumns = true;
} else {
mStretchableColumns = parseColumns(stretchedColumns);
}
}
String shrinkedColumns = a.getString(R.styleable.TableLayout_shrinkColumns);
if (shrinkedColumns != null) {
if (shrinkedColumns.charAt(0) == '*') {
mShrinkAllColumns = true;
} else {
mShrinkableColumns = parseColumns(shrinkedColumns);
}
}
String collapsedColumns = a.getString(R.styleable.TableLayout_collapseColumns);
if (collapsedColumns != null) {
mCollapsedColumns = parseColumns(collapsedColumns);
}
a.recycle();
initTableLayout();
}
/**
* <p>Parses a sequence of columns ids defined in a CharSequence with the
* following pattern (regex): \d+(\s*,\s*\d+)*</p>
*
* <p>Examples: "1" or "13, 7, 6" or "".</p>
*
* <p>The result of the parsing is stored in a sparse boolean array. The
* parsed column ids are used as the keys of the sparse array. The values
* are always true.</p>
*
* @param sequence a sequence of column ids, can be empty but not null
* @return a sparse array of boolean mapping column indexes to the columns
* collapse state
*/
private static SparseBooleanArray parseColumns(String sequence) {
SparseBooleanArray columns = new SparseBooleanArray();
Pattern pattern = Pattern.compile("\\s*,\\s*");
String[] columnDefs = pattern.split(sequence);
for (String columnIdentifier : columnDefs) {
try {
int columnIndex = Integer.parseInt(columnIdentifier);
// only valid, i.e. positive, columns indexes are handled
if (columnIndex >= 0) {
// putting true in this sparse array indicates that the
// column index was defined in the XML file
columns.put(columnIndex, true);
}
} catch (NumberFormatException e) {
// we just ignore columns that don't exist
}
}
return columns;
}
/**
* <p>Performs initialization common to prorgrammatic use and XML use of
* this widget.</p>
*/
private void initTableLayout() {
if (mCollapsedColumns == null) {
mCollapsedColumns = new SparseBooleanArray();
}
if (mStretchableColumns == null) {
mStretchableColumns = new SparseBooleanArray();
}
if (mShrinkableColumns == null) {
mShrinkableColumns = new SparseBooleanArray();
}
// TableLayouts are always in vertical orientation; keep this tracked
// for shared LinearLayout code.
setOrientation(VERTICAL);
mPassThroughListener = new PassThroughHierarchyChangeListener();
// make sure to call the parent class method to avoid potential
// infinite loops
super.setOnHierarchyChangeListener(mPassThroughListener);
mInitialized = true;
}
/**
* {@inheritDoc}
*/
@Override
public void setOnHierarchyChangeListener(
OnHierarchyChangeListener listener) {
// the user listener is delegated to our pass-through listener
mPassThroughListener.mOnHierarchyChangeListener = listener;
}
private void requestRowsLayout() {
if (mInitialized) {
final int count = getChildCount();
for (int i = 0; i < count; i++) {
getChildAt(i).requestLayout();
}
}
}
/**
* {@inheritDoc}
*/
@Override
public void requestLayout() {
if (mInitialized) {
int count = getChildCount();
for (int i = 0; i < count; i++) {
getChildAt(i).forceLayout();
}
}
super.requestLayout();
}
/**
* <p>Indicates whether all columns are shrinkable or not.</p>
*
* @return true if all columns are shrinkable, false otherwise
*
* @attr ref android.R.styleable#TableLayout_shrinkColumns
*/
public boolean isShrinkAllColumns() {
return mShrinkAllColumns;
}
/**
* <p>Convenience method to mark all columns as shrinkable.</p>
*
* @param shrinkAllColumns true to mark all columns shrinkable
*
* @attr ref android.R.styleable#TableLayout_shrinkColumns
*/
public void setShrinkAllColumns(boolean shrinkAllColumns) {
mShrinkAllColumns = shrinkAllColumns;
}
/**
* <p>Indicates whether all columns are stretchable or not.</p>
*
* @return true if all columns are stretchable, false otherwise
*
* @attr ref android.R.styleable#TableLayout_stretchColumns
*/
public boolean isStretchAllColumns() {
return mStretchAllColumns;
}
/**
* <p>Convenience method to mark all columns as stretchable.</p>
*
* @param stretchAllColumns true to mark all columns stretchable
*
* @attr ref android.R.styleable#TableLayout_stretchColumns
*/
public void setStretchAllColumns(boolean stretchAllColumns) {
mStretchAllColumns = stretchAllColumns;
}
/**
* <p>Collapses or restores a given column. When collapsed, a column
* does not appear on screen and the extra space is reclaimed by the
* other columns. A column is collapsed/restored only when it belongs to
* a {@link android.widget.TableRow}.</p>
*
* <p>Calling this method requests a layout operation.</p>
*
* @param columnIndex the index of the column
* @param isCollapsed true if the column must be collapsed, false otherwise
*
* @attr ref android.R.styleable#TableLayout_collapseColumns
*/
public void setColumnCollapsed(int columnIndex, boolean isCollapsed) {
// update the collapse status of the column
mCollapsedColumns.put(columnIndex, isCollapsed);
int count = getChildCount();
for (int i = 0; i < count; i++) {
final View view = getChildAt(i);
if (view instanceof TableRow) {
((TableRow) view).setColumnCollapsed(columnIndex, isCollapsed);
}
}
requestRowsLayout();
}
/**
* <p>Returns the collapsed state of the specified column.</p>
*
* @param columnIndex the index of the column
* @return true if the column is collapsed, false otherwise
*/
public boolean isColumnCollapsed(int columnIndex) {
return mCollapsedColumns.get(columnIndex);
}
/**
* <p>Makes the given column stretchable or not. When stretchable, a column
* takes up as much as available space as possible in its row.</p>
*
* <p>Calling this method requests a layout operation.</p>
*
* @param columnIndex the index of the column
* @param isStretchable true if the column must be stretchable,
* false otherwise. Default is false.
*
* @attr ref android.R.styleable#TableLayout_stretchColumns
*/
public void setColumnStretchable(int columnIndex, boolean isStretchable) {
mStretchableColumns.put(columnIndex, isStretchable);
requestRowsLayout();
}
/**
* <p>Returns whether the specified column is stretchable or not.</p>
*
* @param columnIndex the index of the column
* @return true if the column is stretchable, false otherwise
*/
public boolean isColumnStretchable(int columnIndex) {
return mStretchAllColumns || mStretchableColumns.get(columnIndex);
}
/**
* <p>Makes the given column shrinkable or not. When a row is too wide, the
* table can reclaim extra space from shrinkable columns.</p>
*
* <p>Calling this method requests a layout operation.</p>
*
* @param columnIndex the index of the column
* @param isShrinkable true if the column must be shrinkable,
* false otherwise. Default is false.
*
* @attr ref android.R.styleable#TableLayout_shrinkColumns
*/
public void setColumnShrinkable(int columnIndex, boolean isShrinkable) {
mShrinkableColumns.put(columnIndex, isShrinkable);
requestRowsLayout();
}
/**
* <p>Returns whether the specified column is shrinkable or not.</p>
*
* @param columnIndex the index of the column
* @return true if the column is shrinkable, false otherwise. Default is false.
*/
public boolean isColumnShrinkable(int columnIndex) {
return mShrinkAllColumns || mShrinkableColumns.get(columnIndex);
}
/**
* <p>Applies the columns collapse status to a new row added to this
* table. This method is invoked by PassThroughHierarchyChangeListener
* upon child insertion.</p>
*
* <p>This method only applies to {@link android.widget.TableRow}
* instances.</p>
*
* @param child the newly added child
*/
private void trackCollapsedColumns(View child) {
if (child instanceof TableRow) {
final TableRow row = (TableRow) child;
final SparseBooleanArray collapsedColumns = mCollapsedColumns;
final int count = collapsedColumns.size();
for (int i = 0; i < count; i++) {
int columnIndex = collapsedColumns.keyAt(i);
boolean isCollapsed = collapsedColumns.valueAt(i);
// the collapse status is set only when the column should be
// collapsed; otherwise, this might affect the default
// visibility of the row's children
if (isCollapsed) {
row.setColumnCollapsed(columnIndex, isCollapsed);
}
}
}
}
/**
* {@inheritDoc}
*/
@Override
public void addView(View child) {
super.addView(child);
requestRowsLayout();
}
/**
* {@inheritDoc}
*/
@Override
public void addView(View child, int index) {
super.addView(child, index);
requestRowsLayout();
}
/**
* {@inheritDoc}
*/
@Override
public void addView(View child, ViewGroup.LayoutParams params) {
super.addView(child, params);
requestRowsLayout();
}
/**
* {@inheritDoc}
*/
@Override
public void addView(View child, int index, ViewGroup.LayoutParams params) {
super.addView(child, index, params);
requestRowsLayout();
}
/**
* {@inheritDoc}
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// enforce vertical layout
measureVertical(widthMeasureSpec, heightMeasureSpec);
}
/**
* {@inheritDoc}
*/
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
// enforce vertical layout
layoutVertical(l, t, r, b);
}
/**
* {@inheritDoc}
*/
@Override
void measureChildBeforeLayout(View child, int childIndex,
int widthMeasureSpec, int totalWidth,
int heightMeasureSpec, int totalHeight) {
// when the measured child is a table row, we force the width of its
// children with the widths computed in findLargestCells()
if (child instanceof TableRow) {
((TableRow) child).setColumnsWidthConstraints(mMaxWidths);
}
super.measureChildBeforeLayout(child, childIndex,
widthMeasureSpec, totalWidth, heightMeasureSpec, totalHeight);
}
/**
* {@inheritDoc}
*/
@Override
void measureVertical(int widthMeasureSpec, int heightMeasureSpec) {
findLargestCells(widthMeasureSpec);
shrinkAndStretchColumns(widthMeasureSpec);
super.measureVertical(widthMeasureSpec, heightMeasureSpec);
}
/**
* <p>Finds the largest cell in each column. For each column, the width of
* the largest cell is applied to all the other cells.</p>
*
* @param widthMeasureSpec the measure constraint imposed by our parent
*/
private void findLargestCells(int widthMeasureSpec) {
boolean firstRow = true;
// find the maximum width for each column
// the total number of columns is dynamically changed if we find
// wider rows as we go through the children
// the array is reused for each layout operation; the array can grow
// but never shrinks. Unused extra cells in the array are just ignored
// this behavior avoids to unnecessary grow the array after the first
// layout operation
final int count = getChildCount();
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() == GONE) {
continue;
}
if (child instanceof TableRow) {
final TableRow row = (TableRow) child;
// forces the row's height
final ViewGroup.LayoutParams layoutParams = row.getLayoutParams();
layoutParams.height = LayoutParams.WRAP_CONTENT;
final int[] widths = row.getColumnsWidths(widthMeasureSpec);
final int newLength = widths.length;
// this is the first row, we just need to copy the values
if (firstRow) {
if (mMaxWidths == null || mMaxWidths.length != newLength) {
mMaxWidths = new int[newLength];
}
System.arraycopy(widths, 0, mMaxWidths, 0, newLength);
firstRow = false;
} else {
int length = mMaxWidths.length;
final int difference = newLength - length;
// the current row is wider than the previous rows, so
// we just grow the array and copy the values
if (difference > 0) {
final int[] oldMaxWidths = mMaxWidths;
mMaxWidths = new int[newLength];
System.arraycopy(oldMaxWidths, 0, mMaxWidths, 0,
oldMaxWidths.length);
System.arraycopy(widths, oldMaxWidths.length,
mMaxWidths, oldMaxWidths.length, difference);
}
// the row is narrower or of the same width as the previous
// rows, so we find the maximum width for each column
// if the row is narrower than the previous ones,
// difference will be negative
final int[] maxWidths = mMaxWidths;
length = Math.min(length, newLength);
for (int j = 0; j < length; j++) {
maxWidths[j] = Math.max(maxWidths[j], widths[j]);
}
}
}
}
}
/**
* <p>Shrinks the columns if their total width is greater than the
* width allocated by widthMeasureSpec. When the total width is less
* than the allocated width, this method attempts to stretch columns
* to fill the remaining space.</p>
*
* @param widthMeasureSpec the width measure specification as indicated
* by this widget's parent
*/
private void shrinkAndStretchColumns(int widthMeasureSpec) {
// when we have no row, mMaxWidths is not initialized and the loop
// below could cause a NPE
if (mMaxWidths == null) {
return;
}
// should we honor AT_MOST, EXACTLY and UNSPECIFIED?
int totalWidth = 0;
for (int width : mMaxWidths) {
totalWidth += width;
}
int size = MeasureSpec.getSize(widthMeasureSpec) - mPaddingLeft - mPaddingRight;
if ((totalWidth > size) && (mShrinkAllColumns || mShrinkableColumns.size() > 0)) {
// oops, the largest columns are wider than the row itself
// fairly redistribute the row's width among the columns
mutateColumnsWidth(mShrinkableColumns, mShrinkAllColumns, size, totalWidth);
} else if ((totalWidth < size) && (mStretchAllColumns || mStretchableColumns.size() > 0)) {
// if we have some space left, we distribute it among the
// expandable columns
mutateColumnsWidth(mStretchableColumns, mStretchAllColumns, size, totalWidth);
}
}
private void mutateColumnsWidth(SparseBooleanArray columns,
boolean allColumns, int size, int totalWidth) {
int skipped = 0;
final int[] maxWidths = mMaxWidths;
final int length = maxWidths.length;
final int count = allColumns ? length : columns.size();
final int totalExtraSpace = size - totalWidth;
int extraSpace = totalExtraSpace / count;
// Column's widths are changed: force child table rows to re-measure.
// (done by super.measureVertical after shrinkAndStretchColumns.)
final int nbChildren = getChildCount();
for (int i = 0; i < nbChildren; i++) {
View child = getChildAt(i);
if (child instanceof TableRow) {
child.forceLayout();
}
}
if (!allColumns) {
for (int i = 0; i < count; i++) {
int column = columns.keyAt(i);
if (columns.valueAt(i)) {
if (column < length) {
maxWidths[column] += extraSpace;
} else {
skipped++;
}
}
}
} else {
for (int i = 0; i < count; i++) {
maxWidths[i] += extraSpace;
}
// we don't skip any column so we can return right away
return;
}
if (skipped > 0 && skipped < count) {
// reclaim any extra space we left to columns that don't exist
extraSpace = skipped * extraSpace / (count - skipped);
for (int i = 0; i < count; i++) {
int column = columns.keyAt(i);
if (columns.valueAt(i) && column < length) {
if (extraSpace > maxWidths[column]) {
maxWidths[column] = 0;
} else {
maxWidths[column] += extraSpace;
}
}
}
}
}
/**
* {@inheritDoc}
*/
@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
return new TableLayout.LayoutParams(getContext(), attrs);
}
/**
* Returns a set of layout parameters with a width of
* {@link android.view.ViewGroup.LayoutParams#MATCH_PARENT},
* and a height of {@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT}.
*/
@Override
protected LinearLayout.LayoutParams generateDefaultLayoutParams() {
return new LayoutParams();
}
/**
* {@inheritDoc}
*/
@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
return p instanceof TableLayout.LayoutParams;
}
/**
* {@inheritDoc}
*/
@Override
protected LinearLayout.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
return new LayoutParams(p);
}
@Override
public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(event);
event.setClassName(TableLayout.class.getName());
}
@Override
public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
super.onInitializeAccessibilityNodeInfo(info);
info.setClassName(TableLayout.class.getName());
}
/**
* <p>This set of layout parameters enforces the width of each child to be
* {@link #MATCH_PARENT} and the height of each child to be
* {@link #WRAP_CONTENT}, but only if the height is not specified.</p>
*/
@SuppressWarnings({"UnusedDeclaration"})
public static class LayoutParams extends LinearLayout.LayoutParams {
/**
* {@inheritDoc}
*/
public LayoutParams(Context c, AttributeSet attrs) {
super(c, attrs);
}
/**
* {@inheritDoc}
*/
public LayoutParams(int w, int h) {
super(MATCH_PARENT, h);
}
/**
* {@inheritDoc}
*/
public LayoutParams(int w, int h, float initWeight) {
super(MATCH_PARENT, h, initWeight);
}
/**
* <p>Sets the child width to
* {@link android.view.ViewGroup.LayoutParams} and the child height to
* {@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT}.</p>
*/
public LayoutParams() {
super(MATCH_PARENT, WRAP_CONTENT);
}
/**
* {@inheritDoc}
*/
public LayoutParams(ViewGroup.LayoutParams p) {
super(p);
}
/**
* {@inheritDoc}
*/
public LayoutParams(MarginLayoutParams source) {
super(source);
}
/**
* <p>Fixes the row's width to
* {@link android.view.ViewGroup.LayoutParams#MATCH_PARENT}; the row's
* height is fixed to
* {@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT} if no layout
* height is specified.</p>
*
* @param a the styled attributes set
* @param widthAttr the width attribute to fetch
* @param heightAttr the height attribute to fetch
*/
@Override
protected void setBaseAttributes(TypedArray a,
int widthAttr, int heightAttr) {
this.width = MATCH_PARENT;
if (a.hasValue(heightAttr)) {
this.height = a.getLayoutDimension(heightAttr, "layout_height");
} else {
this.height = WRAP_CONTENT;
}
}
}
/**
* <p>A pass-through listener acts upon the events and dispatches them
* to another listener. This allows the table layout to set its own internal
* hierarchy change listener without preventing the user to setup his.</p>
*/
private class PassThroughHierarchyChangeListener implements
OnHierarchyChangeListener {
private OnHierarchyChangeListener mOnHierarchyChangeListener;
/**
* {@inheritDoc}
*/
public void onChildViewAdded(View parent, View child) {
trackCollapsedColumns(child);
if (mOnHierarchyChangeListener != null) {
mOnHierarchyChangeListener.onChildViewAdded(parent, child);
}
}
/**
* {@inheritDoc}
*/
public void onChildViewRemoved(View parent, View child) {
if (mOnHierarchyChangeListener != null) {
mOnHierarchyChangeListener.onChildViewRemoved(parent, child);
}
}
}
}
|
