TextDisplay.cs

   1 using System;
   2 using System.Timers;
   3 using Cairo;
   4 using Pango;
   5 using Gdk;
   6 using Gtk;
   7
   8 public class TextDisplay : DrawingArea, IKeyPress {
   9         private TextDocument doc = null;
  10         private Pango.Font font;
  11         // FIXME: Proportional fonts?
  12         private float fontWidth;
  13         private float fontHeight;
  14
  15         private Timer helpTimer;
  16         private HelpBox controlHelp;
  17         private bool showHelp;
  18
  19         public TextDisplay() {
  20                 FontDescription fd = Pango.FontDescription.FromString("Courier 12");
  21                 font = this.PangoContext.LoadFont(fd);
  22                 FontMetrics fm = font.GetMetrics(null);
  23                 fontHeight = Pango.Units.ToPixels(fm.Ascent + fm.Descent);
  24                 fontWidth = fontHeight * 0.5333f;
  25                 Console.WriteLine("Using {0} {1}pt ({2}x{3}px)", fd.Family, fd.Size, fontWidth, fontHeight);
  26
  27                 controlHelp = new HelpBox(this.PangoContext, "control_help");
  28                 ModifyBg(StateType.Normal, new Gdk.Color(0xFF, 0xFF, 0xFF));
  29         }
  30
  31         public void SetDocument(TextDocument doc) {
  32                 this.doc = doc;
  33         }
  34
  35         void draw(Cairo.Context gr, int width, int height) {
  36                 if (doc == null) return;
  37
  38                 Pango.Layout layout = new Pango.Layout(this.PangoContext);
  39                 layout.Width = 0x7FFFFFFF; //Pango.Units.FromPixels(width);
  40                 layout.FontDescription = font.Describe();
  41
  42                 //gr.Operator = Operator.Atop;
  43                 gr.SetSourceRGB(0,0,0);
  44                 layout.SetText(doc.GetTextWindow());
  45                 gr.MoveTo(0, 0);
  46                 Pango.CairoHelper.ShowLayout(gr, layout);
  47
  48                 gr.SetSourceRGB(0.0, 0.0, 0.0);
  49                 gr.NewPath();
  50                 gr.Rectangle((doc.cursor.x - doc.textorigin.x)*fontWidth, (doc.cursor.y - doc.textorigin.y)*fontHeight, fontWidth, fontHeight);
  51                 gr.Fill();
  52
  53                 if (showHelp) {
  54                         controlHelp.draw(gr, width, height);
  55                 }
  56         }
  57
  58         protected override bool OnExposeEvent(Gdk.EventExpose args) {
  59                 Gdk.Window win = args.Window;
  60
  61                 #if OLD_SYSTEMS
  62                 //
  63                 // For old versions of Gtk# (before 2.8), you need the helper class
  64                 // available in gtk-sharp/sample/GtkCairo.cs
  65                 //
  66                 Cairo.Context g = Gdk.Graphics.CreateDrawable (win);
  67                 #else
  68                 //
  69                 // Starting with Gtk 2.8 Gtk has direct support for
  70                 // Cairo, as its built on top of it, on older
  71                 // versions, a helper routine is used
  72                 //
  73                 Cairo.Context g = Gdk.CairoHelper.Create (args.Window);
  74                 #endif
  75
  76                 int x, y, w, h, d;
  77                 win.GetGeometry(out x, out y, out w, out h, out d);
  78
  79                 draw (g, w, h);
  80                 ((IDisposable) g.Target).Dispose();
  81                 ((IDisposable) g).Dispose();
  82                 return true;
  83         }
  84
  85         protected override void OnSizeAllocated(Gdk.Rectangle r) {
  86                 base.OnSizeAllocated(r);
  87                 if (doc != null)
  88                         doc.SetPageSize((int)(r.Width / fontWidth) - 1, (int)(r.Height / fontHeight) - 1);
  89         }
  90
  91         public void Update() {
  92                 QueueDraw();
  93         }
  94
  95         public void ShowHelp() {
  96                 showHelp = true;
  97                 helpTimer = null;
  98                 QueueDraw();
  99         }
 100
 101         public void HideHelp() {
 102                 if (helpTimer != null) {
 103                         helpTimer.Stop();
 104                         helpTimer = null;
 105                 }
 106                 if (showHelp)
 107                         showHelp = false;
 108                 QueueDraw();
 109         }
 110
 111         [GLib.ConnectBefore ()]
 112         public void KeyPress(object o, KeyPressEventArgs args) {
 113                 if (doc == null) return;
 114                 if ((args.Event.State & ModifierType.ControlMask) != 0) {
 115                         switch(args.Event.Key) {
 116                         default:
 117                                 HideHelp();
 118                                 break;
 119                         }
 120                 } else {
 121                         switch(args.Event.Key) {
 122                         case Gdk.Key.Control_L:
 123                         case Gdk.Key.Control_R:
 124                                 helpTimer = new Timer();
 125                                 helpTimer.Elapsed += delegate(object o2, ElapsedEventArgs e) {
 126                                         ShowHelp();
 127                                 };
 128                                 helpTimer.AutoReset = false;
 129                                 helpTimer.Interval = 1000;
 130                                 helpTimer.Start();
 131                                 break;
 132                         }
 133                 }
 134                 doc.KeyPress(o, args);
 135         }
 136
 137         public void KeyRelease(object o, KeyReleaseEventArgs e) {
 138                 switch(e.Event.Key) {
 139                 case Gdk.Key.Control_L:
 140                 case Gdk.Key.Control_R:
 141                         HideHelp();
 142                         break;
 143                 }
 144         }
 145 }