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// Copyright (c) 2013-2020 Jean-Philippe Bruyère <jp_bruyere@hotmail.com>
//
// This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
using System;
using System.ComponentModel;
using Glfw;
namespace Crow
{
/// <summary>
/// generic class to build scrolling control in both directions
/// </summary>
[DesignIgnore]
public class ScrollingObject : Widget
{
#region CTOR
protected ScrollingObject () {}
public ScrollingObject (Interface iface, string style = null) : base (iface, style) { }
#endregion
int scrollX, scrollY, maxScrollX, maxScrollY, mouseWheelSpeed;
/// <summary>
/// if true, key stroke are handled in derrived class
/// </summary>
protected bool KeyEventsOverrides = false;
/// <summary> Horizontal Scrolling Position </summary>
[DefaultValue(0)]
public virtual int ScrollX {
get { return scrollX; }
set {
if (scrollX == value)
return;
int newS = value;
if (newS < 0)
newS = 0;
else if (newS > maxScrollX)
newS = maxScrollX;
if (newS == scrollX)
return;
scrollX = newS;
NotifyValueChangedAuto (scrollX);
RegisterForGraphicUpdate ();
}
}
/// <summary> Vertical Scrolling Position </summary>
[DefaultValue(0)]
public virtual int ScrollY {
get { return scrollY; }
set {
if (scrollY == value)
return;
int newS = value;
if (newS < 0)
newS = 0;
else if (newS > maxScrollY)
newS = maxScrollY;
if (newS == scrollY)
return;
scrollY = newS;
NotifyValueChangedAuto (scrollY);
RegisterForGraphicUpdate ();
}
}
/// <summary> Horizontal Scrolling maximum value </summary>
[DefaultValue(0)]
public virtual int MaxScrollX {
get { return maxScrollX; }
set {
if (maxScrollX == value)
return;
maxScrollX = Math.Max(0, value);
if (scrollX > maxScrollX)
ScrollX = maxScrollX;
NotifyValueChangedAuto (maxScrollX);
RegisterForGraphicUpdate ();
}
}
/// <summary> Vertical Scrolling maximum value </summary>
[DefaultValue(0)]
public virtual int MaxScrollY {
get { return maxScrollY; }
set {
if (maxScrollY == value)
return;
maxScrollY = Math.Max (0, value);
if (scrollY > maxScrollY)
ScrollY = maxScrollY;
NotifyValueChangedAuto (maxScrollY);
RegisterForGraphicUpdate ();
}
}
/// <summary> Mouse Wheel Scrolling multiplier </summary>
[DefaultValue(1)]
public virtual int MouseWheelSpeed {
get { return mouseWheelSpeed; }
set {
if (mouseWheelSpeed == value)
return;
mouseWheelSpeed = value;
NotifyValueChangedAuto (mouseWheelSpeed);
}
}
/// <summary> Process scrolling vertically, or if shift is down, vertically </summary>
public override void onMouseWheel (object sender, MouseWheelEventArgs e)
{
base.onMouseWheel (sender, e);
if (IFace.Shift)
ScrollX += e.Delta * MouseWheelSpeed;
else
ScrollY -= e.Delta * MouseWheelSpeed;
}
/// <summary> Process scrolling with arrow keys, home and end keys. </summary>
public override void onKeyDown (object sender, KeyEventArgs e)
{
base.onKeyDown (sender, e);
if (KeyEventsOverrides)
return;
switch (e.Key) {
case Key.Up:
ScrollY--;
break;
case Key.Down:
ScrollY++;
break;
case Key.Left:
ScrollX--;
break;
case Key.Right:
ScrollX++;
break;
case Key.Home:
ScrollX = 0;
ScrollY = 0;
break;
case Key.End:
ScrollX = MaxScrollX;
ScrollY = MaxScrollY;
break;
}
}
}
}
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