[longomatch] Implement zoom out with the Shift modifier

[Andoni Morales Alastruey <amorales src gnome org>]

commit 1204113b09080beb2e98edfbccd3ef4a98468700
Author: Andoni Morales Alastruey <ylatuya gmail com>
Date:   Tue Apr 21 13:01:04 2015 +0200

    Implement zoom out with the Shift modifier

 LongoMatch.Drawing/Widgets/Blackboard.cs |   31 ++++++++++++++++++++++++++++-
 LongoMatch.GUI/Gui/Dialog/DrawingTool.cs |    2 +-
 2 files changed, 30 insertions(+), 3 deletions(-)
---
diff --git a/LongoMatch.Drawing/Widgets/Blackboard.cs b/LongoMatch.Drawing/Widgets/Blackboard.cs
index ef6d706..8adb021 100644
--- a/LongoMatch.Drawing/Widgets/Blackboard.cs
+++ b/LongoMatch.Drawing/Widgets/Blackboard.cs
@@ -40,6 +40,7 @@ namespace LongoMatch.Drawing.Widgets
                DrawTool tool;
                FrameDrawing drawing;
                ISurface backbuffer;
+               ButtonModifier modifier;
                bool handdrawing, inObjectCreation, inZooming;
                double currentZoom;
 
@@ -54,6 +55,7 @@ namespace LongoMatch.Drawing.Widgets
                        FontSize = 12;
                        tool = DrawTool.Selection;
                        currentZoom = 1;
+                       MinZoom = 1;
                        MaxZoom = 4;
                }
 
@@ -176,6 +178,14 @@ namespace LongoMatch.Drawing.Widgets
                }
 
                /// <summary>
+               /// Sets the minimum zoom allowed
+               /// </summary>
+               public double MinZoom {
+                       get;
+                       set;
+               }
+
+               /// <summary>
                /// Deletes the current selection from the frame drawing.
                /// </summary>
                public void DeleteSelection ()
@@ -365,8 +375,19 @@ namespace LongoMatch.Drawing.Widgets
                                handdrawing = true;
                                break;
                        case DrawTool.Zoom:
-                               Zoom (Math.Min (currentZoom + 0.1, MaxZoom), MoveStart);
-                               break;
+                               {
+                                       double newZoom = currentZoom;
+
+                                       if (modifier == ButtonModifier.Shift) {
+                                               newZoom -= 0.1;
+                                       } else {
+                                               newZoom += 0.1;
+                                       }
+                                       newZoom = Math.Max (newZoom, MinZoom);
+                                       newZoom = Math.Min (newZoom, MaxZoom);
+                                       Zoom (newZoom, MoveStart);
+                                       break;
+                               }
                        }
 
                        if (drawable != null) {
@@ -431,6 +452,12 @@ namespace LongoMatch.Drawing.Widgets
                        }
                }
 
+               protected override void HandleLeftButton (Point coords, ButtonModifier modif)
+               {
+                       modifier = modif;
+                       base.HandleLeftButton (coords, modif);
+               }
+
                void UpdateCounters ()
                {
                        int index = 1;
diff --git a/LongoMatch.GUI/Gui/Dialog/DrawingTool.cs b/LongoMatch.GUI/Gui/Dialog/DrawingTool.cs
index d71baf6..8fb53cb 100644
--- a/LongoMatch.GUI/Gui/Dialog/DrawingTool.cs
+++ b/LongoMatch.GUI/Gui/Dialog/DrawingTool.cs
@@ -107,7 +107,7 @@ namespace LongoMatch.Gui.Dialog
                        stylecombobox.TooltipMarkup = Catalog.GetString ("Change the line style");
                        typecombobox.TooltipMarkup = Catalog.GetString ("Change the line style");
                        clearbutton.TooltipMarkup = Catalog.GetString ("Clear all drawings");
-                       zoombutton.TooltipMarkup = Catalog.GetString ("Zoom tool. Click to zoom in, Alt+Click 
to zoom out");
+                       zoombutton.TooltipMarkup = Catalog.GetString ("Zoom tool. Click to zoom in, Alt+Shift 
to zoom out");
 
                        FillLineStyle ();
                        FillLineType ();