xwt/Xwt.WPF/Xwt.WPFBackend/PanedBackend.cs

377 строки
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C#

//
// PanedBackend.cs
//
// Author:
// Eric Maupin <ermau@xamarin.com>
// Lluis Sanchez <lluis@xamarin.com>
//
// Copyright (c) 2012 Xamarin, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
using System;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using Xwt.Backends;
using Orientation = Xwt.Backends.Orientation;
using SW = System.Windows;
using SWC = System.Windows.Controls;
using System.Collections.Generic;
namespace Xwt.WPFBackend
{
public class PanedBackend
: WidgetBackend, IPanedBackend
{
double position = -1;
Orientation direction;
PanelInfo panel1 = new PanelInfo ();
PanelInfo panel2 = new PanelInfo ();
GridSplitter splitter;
private const int SplitterSize = 4;
private bool reportPositionChanged;
double lastSize;
class PanelInfo
{
public UIElement Widget;
public bool Resize;
public DefinitionBase Definition;
public int PanelIndex;
public bool Shrink;
public WidgetBackend Backend;
public bool HasWidget { get { return Widget != null; } }
public IWidgetSurface WidgetSurface {
get { return (IWidgetSurface)Backend.Frontend; }
}
public GridLength Size
{
get
{
if (Definition is ColumnDefinition)
return ((ColumnDefinition)Definition).Width;
else
return ((RowDefinition)Definition).Height;
}
set
{
if (Definition is ColumnDefinition)
((ColumnDefinition)Definition).Width = value;
else
((RowDefinition)Definition).Height = value;
}
}
}
public void Initialize (Orientation dir)
{
this.direction = dir;
Grid = new PanedGrid () { Backend = this };
// Create all the row/column definitions and the splitter
if (direction == Orientation.Horizontal) {
ColumnDefinition definition = new ColumnDefinition ();
definition.Width = new GridLength (1, GridUnitType.Star);
Grid.ColumnDefinitions.Add (definition);
panel1.Definition = definition;
splitter = new GridSplitter {
ResizeDirection = GridResizeDirection.Columns,
VerticalAlignment = VerticalAlignment.Stretch,
HorizontalAlignment = HorizontalAlignment.Center,
Width = SplitterSize
};
Grid.ColumnDefinitions.Add (new ColumnDefinition { Width = GridLength.Auto });
Grid.SetColumn (splitter, 1);
Grid.Children.Add (splitter);
definition = new ColumnDefinition ();
definition.Width = new GridLength (1, GridUnitType.Star);
Grid.ColumnDefinitions.Add (definition);
panel2.Definition = definition;
}
else {
RowDefinition definition = new RowDefinition ();
definition.Height = new GridLength (1, GridUnitType.Star);
Grid.RowDefinitions.Add (definition);
panel1.Definition = definition;
splitter = new GridSplitter {
ResizeDirection = GridResizeDirection.Rows,
HorizontalAlignment = HorizontalAlignment.Stretch,
VerticalAlignment = VerticalAlignment.Center,
Height = SplitterSize
};
Grid.RowDefinitions.Add (new RowDefinition { Height = GridLength.Auto });
Grid.SetRow (splitter, 1);
Grid.Children.Add (splitter);
definition = new RowDefinition ();
definition.Height = new GridLength (1, GridUnitType.Star);
Grid.RowDefinitions.Add (definition);
panel2.Definition = definition;
}
panel1.PanelIndex = 0;
panel2.PanelIndex = 2;
splitter.Visibility = Visibility.Hidden;
splitter.DragDelta += delegate
{
if (position != panel1.Size.Value) {
position = panel1.Size.Value;
NotifyPositionChanged ();
}
};
}
public double Position
{
get {
return position != -1 ? position : 0;
}
set {
if (position != value) {
position = value;
NotifyPositionChanged ();
}
}
}
internal void NotifyPositionChanged ()
{
if (this.reportPositionChanged)
Context.InvokeUserCode (((IPanedEventSink)EventSink).OnPositionChanged);
}
PanelInfo GetPanel (int panel)
{
return panel == 1 ? panel1 : panel2;
}
bool SplitterVisible
{
get { return panel1.HasWidget && panel2.HasWidget; }
}
public void SetPanel (int panel, IWidgetBackend widget, bool resize, bool shrink)
{
var panelWidget = (UIElement)widget.NativeWidget;
var pi = GetPanel (panel);
pi.Widget = panelWidget;
pi.Backend = (WidgetBackend)widget;
pi.Resize = resize;
pi.Shrink = shrink;
if (direction == Orientation.Horizontal)
Grid.SetColumn (pi.Widget, pi.PanelIndex);
else
Grid.SetRow (pi.Widget, pi.PanelIndex);
Grid.Children.Add (pi.Widget);
UpdateSplitterVisibility ();
}
public void UpdatePanel (int panel, bool resize, bool shrink)
{
var pi = GetPanel (panel);
pi.Resize = resize;
pi.Shrink = shrink;
Grid.InvalidateArrange ();
}
public void RemovePanel (int panel)
{
var pi = GetPanel (panel);
Grid.Children.Remove (pi.Widget);
pi.Widget = null;
UpdateSplitterVisibility ();
}
public override Size GetPreferredSize (SizeConstraint widthConstraint, SizeConstraint heightConstraint)
{
if (panel1.HasWidget && panel2.HasWidget) {
double w, h;
if (direction == Orientation.Horizontal) {
var s1 = panel1.WidgetSurface.GetPreferredSize (SizeConstraint.Unconstrained, heightConstraint);
var s2 = panel2.WidgetSurface.GetPreferredSize (SizeConstraint.Unconstrained, heightConstraint);
w = s1.Width + s2.Width + SplitterSize;
h = Math.Max (s1.Height, s2.Height);
}
else {
var s1 = panel1.WidgetSurface.GetPreferredSize (widthConstraint, SizeConstraint.Unconstrained);
var s2 = panel2.WidgetSurface.GetPreferredSize (widthConstraint, SizeConstraint.Unconstrained);
h = s1.Height + s2.Height + SplitterSize;
w = Math.Max (s1.Width, s2.Width);
}
if (direction == Orientation.Horizontal && widthConstraint.IsConstrained && w > widthConstraint.AvailableSize)
w = widthConstraint.AvailableSize;
if (direction == Orientation.Vertical && heightConstraint.IsConstrained && h > heightConstraint.AvailableSize)
h = heightConstraint.AvailableSize;
return new Size (w, h);
}
else if (panel1.HasWidget)
return panel1.WidgetSurface.GetPreferredSize (widthConstraint, heightConstraint);
else if (panel2.HasWidget)
return panel2.WidgetSurface.GetPreferredSize (widthConstraint, heightConstraint);
else
return Size.Zero;
}
internal void ArrangeChildren (SW.Size size)
{
double newSize = direction == Orientation.Horizontal ? size.Width : size.Height;
double splitterDesiredSize = SplitterSize;
double availableSize;
availableSize = newSize - splitterDesiredSize;
if (availableSize <= 0)
return;
if (panel1.Widget != null && panel2.Widget != null) {
// If the bounds have changed, we have to calculate a new current position
if (lastSize != newSize || position == -1) {
double oldAvailableSize = lastSize - SplitterSize;
if (position == -1)
position = availableSize / 2;
else if (IsFixed (panel2)) {
var oldPanel2Size = oldAvailableSize - position - SplitterSize;
position = availableSize - oldPanel2Size - SplitterSize;
}
else if (!IsFixed (panel1) && lastSize != 0)
position = availableSize * (position / oldAvailableSize);
}
if (!panel1.Shrink) {
var w = panel1.WidgetSurface;
var min = direction == Orientation.Horizontal ? w.GetPreferredSize ().Width: w.GetPreferredSize ().Height;
if (position < min)
position = min;
}
if (!panel2.Shrink) {
var w = panel2.WidgetSurface;
var min = direction == Orientation.Horizontal ? w.GetPreferredSize ().Width : w.GetPreferredSize ().Height;
if (availableSize - position < min) {
position = availableSize - min;
}
}
if (position < 0)
position = 0;
if (position > availableSize)
position = availableSize;
panel1.Size = new GridLength (position, GridUnitType.Star);
panel2.Size = new GridLength (availableSize - position, GridUnitType.Star);
} else if (panel1.Widget != null) {
panel1.Size = new GridLength (1, GridUnitType.Star);
panel2.Size = new GridLength(0);
} else if (panel2 != null) {
panel2.Size = new GridLength(1, GridUnitType.Star);
panel1.Size = new GridLength(0);
}
lastSize = newSize;
}
bool IsFixed (PanelInfo pi)
{
return !pi.Resize && (pi == panel1 ? panel2 : panel1).Resize;
}
void UpdateSplitterVisibility ()
{
if (panel1.Widget != null && panel2.Widget != null)
splitter.Visibility = Visibility.Visible;
else
splitter.Visibility = Visibility.Hidden;
}
public override void EnableEvent (object eventId)
{
base.EnableEvent (eventId);
if (eventId is PanedEvent) {
switch ((PanedEvent)eventId) {
case PanedEvent.PositionChanged:
this.reportPositionChanged = true;
break;
}
}
}
public override void DisableEvent (object eventId)
{
base.DisableEvent (eventId);
if (eventId is PanedEvent) {
switch ((PanedEvent)eventId) {
case PanedEvent.PositionChanged:
this.reportPositionChanged = false;
break;
}
}
}
private Grid Grid
{
get { return (Grid) Widget; }
set { Widget = value; }
}
}
class PanedGrid: Grid, IWpfWidget
{
public WidgetBackend Backend { get; set; }
protected override SW.Size MeasureOverride (SW.Size constraint)
{
// HACK: Fixes invalid size measure
// This line is hack to fix a measuring issue with Grid. For some reason, the grid 'remembers' the constraint
// parameter, so if MeasureOverride is called with a constraining size, but ArrangeOverride is later called
// with a bigger size, the Grid still uses the constrained size when determining the size of the children
//constraint = new SW.Size (double.PositiveInfinity, double.PositiveInfinity);
var s = base.MeasureOverride (constraint);
return Backend.MeasureOverride (constraint, s);
}
protected override System.Windows.Size ArrangeOverride (System.Windows.Size arrangeSize)
{
PanedBackend b = ((PanedBackend)Backend);
var oldPos = b.Position;
b.ArrangeChildren (arrangeSize);
var s = base.ArrangeOverride (arrangeSize);
if (oldPos != b.Position)
b.NotifyPositionChanged ();
return s;
}
}
}