mcs/class/Managed.Windows.Forms/System.Windows.Forms/XEventQueue.cs

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  12 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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  20 // Copyright (c) 2004-2006 Novell, Inc.
  21 //
  22 // System.Windows.Forms.XEventQueue
  23 //
  24 // Authors:
  25 //  Jackson Harper (jackson@ximian.com)
  26 //  Peter Dennis Bartok (pbartok@novell.com)
  27 //
  28
  29 using System;
  30 using System.Threading;
  31 using System.Collections;
  32
  33 namespace System.Windows.Forms {
  34
  35         internal class XEventQueue {
  36
  37                 private XQueue          xqueue;
  38                 private XQueue          lqueue; // Events inserted from threads other then the main X thread
  39                 private PaintQueue      paint;  // Paint-only queue
  40                 private Thread          thread;
  41
  42                 private static readonly int InitialXEventSize = 100;
  43                 private static readonly int InitialLXEventSize = 10;
  44                 private static readonly int InitialPaintSize = 50;
  45
  46                 public XEventQueue (Thread thread) {
  47                         xqueue = new XQueue (InitialXEventSize);
  48                         lqueue = new XQueue (InitialLXEventSize);
  49                         paint = new PaintQueue(InitialPaintSize);
  50                         this.thread = thread;
  51                 }
  52
  53                 public int Count {
  54                         get {
  55                                 lock (lqueue) {
  56                                         return xqueue.Count + lqueue.Count;
  57                                 }
  58                         }
  59                 }
  60
  61                 public PaintQueue Paint {
  62                         get {
  63                                 return paint;
  64                         }
  65                 }
  66
  67                 public Thread Thread {
  68                         get {
  69                                 return thread;
  70                         }
  71                 }
  72
  73                 public void Enqueue (XEvent xevent)
  74                 {
  75                         xqueue.Enqueue (xevent);
  76                 }
  77
  78                 public void EnqueueLocked (XEvent xevent)
  79                 {
  80                         lock (lqueue) {
  81                                 lqueue.Enqueue (xevent);
  82                         }
  83                 }
  84
  85                 public XEvent Dequeue ()
  86                 {
  87                         if (xqueue.Count == 0) {
  88                                 lock (lqueue) {
  89                                         return lqueue.Dequeue ();
  90                                 }
  91                         }
  92                         return xqueue.Dequeue ();
  93                 }
  94
  95                 public class PaintQueue {
  96
  97                         private ArrayList       hwnds;
  98                         private XEvent          xevent;
  99
 100                         public PaintQueue (int size) {
 101                                 hwnds = new ArrayList(size);
 102                                 xevent = new XEvent();
 103                                 xevent.AnyEvent.type = XEventName.Expose;
 104                         }
 105
 106                         public int Count {
 107                                 get { return hwnds.Count; }
 108                         }
 109
 110                         public void Enqueue (Hwnd hwnd) {
 111                                 hwnds.Add(hwnd);
 112                         }
 113
 114                         public void Remove(Hwnd hwnd) {
 115                                 if (!hwnd.expose_pending && !hwnd.nc_expose_pending) {
 116                                         hwnds.Remove(hwnd);
 117                                 }
 118                         }
 119
 120                         public XEvent Dequeue () {
 121                                 Hwnd            hwnd;
 122                                 IEnumerator     next;
 123
 124                                 if (hwnds.Count == 0) {
 125                                         xevent.ExposeEvent.window = IntPtr.Zero;
 126                                         return xevent;
 127                                 }
 128
 129                                 next = hwnds.GetEnumerator();
 130                                 next.MoveNext();
 131                                 hwnd = (Hwnd)next.Current;
 132
 133                                 // We only remove the event from the queue if we have one expose left since
 134                                 // a single 'entry in our queue may be for both NC and Client exposed
 135                                 if ( !(hwnd.nc_expose_pending && hwnd.expose_pending)) {
 136                                         hwnds.Remove(hwnd);
 137                                 }
 138                                 if (hwnd.expose_pending) {
 139                                         xevent.ExposeEvent.window = hwnd.client_window;
 140 #if not
 141                                         xevent.ExposeEvent.x = hwnd.invalid.X;
 142                                         xevent.ExposeEvent.y = hwnd.invalid.Y;
 143                                         xevent.ExposeEvent.width = hwnd.invalid.Width;
 144                                         xevent.ExposeEvent.height = hwnd.invalid.Height;
 145 #endif
 146                                         return xevent;
 147                                 } else {
 148                                         xevent.ExposeEvent.window = hwnd.whole_window;
 149                                         xevent.ExposeEvent.x = hwnd.nc_invalid.X;
 150                                         xevent.ExposeEvent.y = hwnd.nc_invalid.Y;
 151                                         xevent.ExposeEvent.width = hwnd.nc_invalid.Width;
 152                                         xevent.ExposeEvent.height = hwnd.nc_invalid.Height;
 153                                         return xevent;
 154                                 }
 155                         }
 156                 }
 157
 158                 private class XQueue {
 159
 160                         private XEvent [] xevents;
 161                         private int head;
 162                         private int tail;
 163                         private int size;
 164
 165                         public XQueue (int size)
 166                         {
 167                                 xevents = new XEvent [size];
 168                         }
 169
 170                         public int Count {
 171                                 get { return size; }
 172                         }
 173
 174                         public void Enqueue (XEvent xevent)
 175                         {
 176                                 if (size == xevents.Length)
 177                                         Grow ();
 178
 179                                 xevents [tail] = xevent;
 180                                 tail = (tail + 1) % xevents.Length;
 181                                 size++;
 182                         }
 183
 184                         public XEvent Dequeue ()
 185                         {
 186                                 if (size < 1)
 187                                         throw new Exception ("Attempt to dequeue empty queue.");
 188                                 XEvent res = xevents [head];
 189                                 head = (head + 1) % xevents.Length;
 190                                 size--;
 191                                 return res;
 192                         }
 193
 194                         private void Grow ()
 195                         {
 196                                 int newcap = (xevents.Length * 2);
 197                                 XEvent [] na = new XEvent [newcap];
 198                                 xevents.CopyTo (na, 0);
 199                                 xevents = na;
 200                                 head = 0;
 201                                 tail = head + size;
 202                         }
 203                 }
 204         }
 205 }
 206