1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273 | ------------------------------------------------------------------------------
-- GtkAda - Ada95 binding for the Gimp Toolkit --
-- --
-- Copyright (C) 2014-2018, AdaCore --
-- --
-- This library is free software; you can redistribute it and/or modify it --
-- under terms of the GNU General Public License as published by the Free --
-- Software Foundation; either version 3, or (at your option) any later --
-- version. This library is distributed in the hope that it will be useful, --
-- but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHAN- --
-- TABILITY or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
------------------------------------------------------------------------------
with Ada.Tags; use Ada.Tags;
with Cairo; use Cairo;
with Glib; use Glib;
with Glib.Object; use Glib.Object;
with Gdk.RGBA; use Gdk.RGBA;
with Gdk.Types; use Gdk.Types;
with Gtk.Enums; use Gtk.Enums;
with Gtk.Scrolled_Window; use Gtk.Scrolled_Window;
with Gtk.Widget; use Gtk.Widget;
with Gtkada.Canvas_View; use Gtkada.Canvas_View;
with Gtkada.Canvas_View.Views; use Gtkada.Canvas_View.Views;
with Gtkada.Style; use Gtkada.Style;
with Pango.Font; use Pango.Font;
package body Create_Canvas_View_Events is
type Demo_View_Record is new Canvas_View_Record with record
Console : Text_Item;
-- A text item that reports the events from the view.
end record;
type Demo_View is access all Demo_View_Record'Class;
overriding procedure Draw_Internal
(Self : not null access Demo_View_Record;
Context : Draw_Context;
Area : Model_Rectangle);
function On_Item_Event
(View : not null access GObject_Record'Class;
Event : Event_Details_Access)
return Boolean;
-- Called when the canvas reports an event
function On_Item_Event_Zoom is new On_Item_Event_Zoom_Generic
(Modifier => Mod1_Mask);
function On_Item_Event_Key_Navigate
is new On_Item_Event_Key_Navigate_Generic (Modifier => Mod1_Mask);
function On_Item_Event_Key_Scrolls is new On_Item_Event_Key_Scrolls_Generic
(Modifier => 0);
----------
-- Help --
----------
function Help return String is
begin
return "This demo illustrates the @binteractive@B features of the"
& " Canvas_View widget."
& ASCII.LF
& "By default, this widget provides very limited handling events."
& " It knows how to scroll when inserted in a Gtk_Scrolled_Window,"
& " including reacting to mouse wheels and touchpad events for the"
& " scrolling."
& ASCII.LF
& "But if you want more advanced behavior (@bselection@B of items,"
& " @bmoving items@B with the mouse or keyboard, @bzooming@B in or"
& " out, ...) you will need to connect to the signals emitted by"
& " the view, in particular ""@bitem_event@B""."
& ASCII.LF
& "This demo shows the following capabilities:" & ASCII.LF
& " - @bdragging items@B with the mouse. Items will tend to @bsnap@B"
& " to the grid when they get close enough to it, but they are"
& " not constrained to grid coordinates. Snapping is disabled if you"
& " press shift during the move. Items will also snap on @bsmart"
& " guides@B, which are lines matching various points of interest"
& " from the other items. This provides a convenient way to align"
& " items."
& ASCII.LF
& " - @boverlap@B avoidance: when an item is moved on top of another"
& " item, the latter is moved aside."
& ASCII.LF
& " - @bscrolling@B by dragging the background with the mouse."
& ASCII.LF
& " - @bzooming@B with alt-mouse wheel." & ASCII.LF
& " - @bkeys@B can be used to move the selected items, or scroll the"
& " view when no item is selected." & ASCII.LF
& " - @bkeys@B can also be used to navigate between items, by"
& " pressing @balt@B at the same time as the keyboard arrows.";
end Help;
-------------------
-- Draw_Internal --
-------------------
overriding procedure Draw_Internal
(Self : not null access Demo_View_Record;
Context : Draw_Context;
Area : Model_Rectangle)
is
P : Cairo_Pattern;
B : constant Model_Rectangle := Self.Get_Visible_Area;
begin
P := Pattern_Create_Linear
(X0 => B.X,
Y0 => B.Y,
X1 => B.X + B.Width,
Y1 => B.Y + B.Height);
Pattern_Add_Color_Stop_Rgb (P, 0.0, 0.76, 0.9, 0.4);
Pattern_Add_Color_Stop_Rgb (P, 0.7, 0.76, 0.9, 0.4);
Pattern_Add_Color_Stop_Rgb (P, 1.0, 0.0, 0.0, 0.0);
Draw_Grid_Lines
(Self => Self,
Style => Gtk_New (Stroke => (0.8, 0.8, 0.8, 0.8),
Fill => P),
Context => Context,
Area => Area);
Pattern_Destroy (P);
Canvas_View_Record (Self.all).Draw_Internal (Context, Area);
end Draw_Internal;
-------------------
-- On_Item_Event --
-------------------
function On_Item_Event
(View : not null access GObject_Record'Class;
Event : Event_Details_Access)
return Boolean
is
Self : constant Demo_View := Demo_View (View);
Base_Text : constant String :=
Canvas_Event_Type'Image (Event.Event_Type)
& " (button" & Guint'Image (Event.Button) & ")";
begin
if Event.Toplevel_Item /= null then
Self.Console.Set_Text
(Base_Text & " on "
& External_Tag (Event.Toplevel_Item'Tag));
else
Self.Console.Set_Text (Base_Text);
end if;
-- layout changed, since the size of the console has changed
Self.Model.Refresh_Layout;
return False; -- fallback to other handlers
end On_Item_Event;
---------
-- Run --
---------
procedure Run (Frame : access Gtk.Frame.Gtk_Frame_Record'Class) is
S : constant Gdouble := 0.86602540378443864676; -- sqrt(3) / 2
Canvas : Demo_View;
Model : List_Canvas_Model;
Scrolled : Gtk_Scrolled_Window;
Black, Font : Drawing_Style;
L1, L2, L3 : Canvas_Link;
It1, It3 : Rect_Item;
It2 : Polyline_Item;
Ellipse : Ellipse_Item;
L : Gdouble;
begin
Gtk_New (Model);
Model.Set_Selection_Mode (Selection_Multiple);
Canvas := new Demo_View_Record;
Gtkada.Canvas_View.Initialize (Canvas);
Canvas.Set_Grid_Size (30.0);
Canvas.Avoid_Overlap (True);
Canvas.Set_Snap (Snap_To_Grid => True,
Snap_To_Guides => True);
-- Connect this one first so that all events are traced
Canvas.On_Item_Event (On_Item_Event'Access);
-- Order is irrelevant here.
Canvas.On_Item_Event (On_Item_Event_Select'Access);
Canvas.On_Item_Event (On_Item_Event_Move_Item'Access);
Canvas.On_Item_Event (On_Item_Event_Scroll_Background'Access);
Canvas.On_Item_Event (On_Item_Event_Key_Navigate'Access);
Canvas.On_Item_Event (On_Item_Event_Key_Scrolls'Access);
Canvas.On_Item_Event (On_Item_Event_Zoom'Access);
Font := Gtk_New (Stroke => Null_RGBA,
Font => (Name => From_String ("sans 8"),
others => <>));
Canvas.Console := Gtk_New_Text (Font, "");
Canvas.Console.Set_Position ((0.0, 0.0));
Model.Add (Canvas.Console);
Black := Gtk_New (Fill => Create_Rgba_Pattern ((1.0, 0.0, 0.0, 1.0)));
It1 := Gtk_New_Rect (Black, 80.0, 80.0);
It1.Set_Position ((50.0, 50.0));
Model.Add (It1);
L := 30.0;
It2 := Gtk_New_Polyline
(Gtk_New (Fill => Create_Rgba_Pattern ((1.0, 0.0, 0.0, 1.0)),
Shadow => (Color => (0.0, 0.0, 0.0, 0.1), others => <>)),
((2.0 * L, L * S),
(1.5 * L, L * S * 2.0),
(0.5 * L, L * S * 2.0),
(0.0, L * S),
(0.5 * L, 0.0),
(1.5 * L, 0.0)),
Close => True);
It2.Set_Position ((250.0, 250.0));
Model.Add (It2);
It3 := Gtk_New_Rect
(Gtk_New (Fill => Create_Rgba_Pattern ((0.0, 1.0, 0.0, 1.0)),
Shadow => (Color => (0.0, 0.0, 0.0, 0.1), others => <>)),
50.0, 80.0);
It3.Set_Position ((50.0, 220.0));
Model.Add (It3);
L1 := Gtk_New (From => It1, To => It2, Style => Gtk_New,
Routing => Straight);
Model.Add (L1);
L2 := Gtk_New (From => It2, To => It3, Style => Gtk_New,
Routing => Straight);
Model.Add (L2);
L3 := Gtk_New (From => L1, To => L2,
Style => Gtk_New (Dashes => (4.0, 4.0)),
Routing => Straight);
Model.Add (L3);
It3 := Gtk_New_Rect (Black, 50.0, 80.0);
It3.Set_Position ((650.0, 400.0));
Model.Add (It3);
Ellipse := Gtk_New_Ellipse
(Gtk_New (Fill => Create_Rgba_Pattern ((1.0, 0.0, 0.0, 1.0)),
Shadow => (Color => (0.0, 0.0, 0.0, 0.1), others => <>)),
Width => 70.0, Height => 40.0);
Ellipse.Set_Position ((200.0, 30.0));
Model.Add (Ellipse);
-- Create the view once the model is populated, to avoid a refresh
-- every time a new item is added.
Gtk_New (Scrolled);
Scrolled.Set_Policy (Policy_Always, Policy_Always);
Frame.Add (Scrolled);
Canvas.Set_Model (Model);
Unref (Model);
Scrolled.Add (Canvas);
Frame.Show_All;
end Run;
end Create_Canvas_View_Events;
|