/*
* Copyright 2019 faddenSoft
*
* 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.
*/
using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Windows.Controls;
using CommonUtil;
namespace SourceGenWPF {
///
/// Tracks the items selected in the DisplayList.
///
/// Forward the SelectionChanged event. In WPF you can't get indices, only items, so we
/// have to store the item index in the item itself.
///
public class DisplayListSelection {
private BitArray mSelection;
///
/// Retrieves the total number of boolean values in the set. This is NOT the
/// number of selected items.
///
public int Length { get { return mSelection.Length; } }
///
/// Sets or gets the Nth element. True means the line is selected.
///
public bool this[int key] {
get {
return mSelection[key];
}
set {
mSelection[key] = value;
}
}
public DisplayListSelection() {
mSelection = new BitArray(0);
}
public DisplayListSelection(int length) {
mSelection = new BitArray(length);
}
///
/// Sets the length of the selection array.
///
/// If the new length is longer, the new elements are initialized to false. If the
/// new length is shorter, the excess elements are discarded. (This matches the behavior
/// of a virtual ListView selection set.)
///
/// New length.
public void SetLength(int length) {
//Debug.WriteLine("VirtualListViewSelection length now " + length);
mSelection.Length = length;
}
///
/// Handles selection change.
///
/// Argument from SelectionChanged event.
public void SelectionChanged(SelectionChangedEventArgs e) {
foreach (DisplayList.FormattedParts parts in e.AddedItems) {
Debug.Assert(parts.ListIndex >= 0 && parts.ListIndex < mSelection.Length);
mSelection.Set(parts.ListIndex, true);
}
foreach (DisplayList.FormattedParts parts in e.RemovedItems) {
Debug.Assert(parts.ListIndex >= 0 && parts.ListIndex < mSelection.Length);
mSelection.Set(parts.ListIndex, false);
}
}
///
/// Confirms that the selection count matches the number of set bits. Pass
/// in {ListView}.SelectedIndices.Count.
///
/// Expected number of selected entries.
/// True if count matches.
public bool DebugValidateSelectionCount(int expected) {
int actual = 0;
foreach (bool bit in mSelection) {
if (bit) {
actual++;
}
}
if (actual != expected) {
Debug.WriteLine("SelectionCount expected " + expected + ", actual " + actual);
}
return (actual == expected);
}
public void DebugDump() {
RangeSet rangeSet = new RangeSet();
for (int i = 0; i < mSelection.Length; i++) {
if (mSelection[i]) {
rangeSet.Add(i);
}
}
Debug.WriteLine("VirtualListViewSelection ranges:");
IEnumerator iter = rangeSet.RangeListIterator;
while (iter.MoveNext()) {
RangeSet.Range range = iter.Current;
Debug.WriteLine(" [" + range.Low.ToString() + "," + range.High.ToString() + "]");
}
}
}
}