xref: /glogg/src/viewtools.h (revision 0b05c6ea46705863f3900632518ecea058e08001)
1*0b05c6eaSNicolas Bonnefon /*
2*0b05c6eaSNicolas Bonnefon  * Copyright (C) 2015 Nicolas Bonnefon and other contributors
3*0b05c6eaSNicolas Bonnefon  *
4*0b05c6eaSNicolas Bonnefon  * This file is part of glogg.
5*0b05c6eaSNicolas Bonnefon  *
6*0b05c6eaSNicolas Bonnefon  * glogg is free software: you can redistribute it and/or modify
7*0b05c6eaSNicolas Bonnefon  * it under the terms of the GNU General Public License as published by
8*0b05c6eaSNicolas Bonnefon  * the Free Software Foundation, either version 3 of the License, or
9*0b05c6eaSNicolas Bonnefon  * (at your option) any later version.
10*0b05c6eaSNicolas Bonnefon  *
11*0b05c6eaSNicolas Bonnefon  * glogg is distributed in the hope that it will be useful,
12*0b05c6eaSNicolas Bonnefon  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13*0b05c6eaSNicolas Bonnefon  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14*0b05c6eaSNicolas Bonnefon  * GNU General Public License for more details.
15*0b05c6eaSNicolas Bonnefon  *
16*0b05c6eaSNicolas Bonnefon  * You should have received a copy of the GNU General Public License
17*0b05c6eaSNicolas Bonnefon  * along with glogg.  If not, see <http://www.gnu.org/licenses/>.
18*0b05c6eaSNicolas Bonnefon  */
19*0b05c6eaSNicolas Bonnefon 
20*0b05c6eaSNicolas Bonnefon #ifndef VIEWTOOLS_H
21*0b05c6eaSNicolas Bonnefon #define VIEWTOOLS_H
22*0b05c6eaSNicolas Bonnefon 
23*0b05c6eaSNicolas Bonnefon #include <QObject>
24*0b05c6eaSNicolas Bonnefon 
25*0b05c6eaSNicolas Bonnefon // This class is a controller for an elastic hook manipulated with
26*0b05c6eaSNicolas Bonnefon // the mouse wheel or touchpad.
27*0b05c6eaSNicolas Bonnefon // It is used for the "follow" line at the end of the file.
28*0b05c6eaSNicolas Bonnefon class ElasticHook : public QObject {
29*0b05c6eaSNicolas Bonnefon   Q_OBJECT
30*0b05c6eaSNicolas Bonnefon 
31*0b05c6eaSNicolas Bonnefon   public:
32*0b05c6eaSNicolas Bonnefon     ElasticHook( int hook_threshold ) {
33*0b05c6eaSNicolas Bonnefon         hook_threshold_ = hook_threshold;
34*0b05c6eaSNicolas Bonnefon     }
35*0b05c6eaSNicolas Bonnefon 
36*0b05c6eaSNicolas Bonnefon     // Instruct the elastic to move by the passed pixels
37*0b05c6eaSNicolas Bonnefon     // (a positive value increase the elastic tension)
38*0b05c6eaSNicolas Bonnefon     void move( int value );
39*0b05c6eaSNicolas Bonnefon 
40*0b05c6eaSNicolas Bonnefon     int length() const { return position_; }
41*0b05c6eaSNicolas Bonnefon 
42*0b05c6eaSNicolas Bonnefon   protected:
43*0b05c6eaSNicolas Bonnefon     void timerEvent( QTimerEvent *event );
44*0b05c6eaSNicolas Bonnefon 
45*0b05c6eaSNicolas Bonnefon   signals:
46*0b05c6eaSNicolas Bonnefon     // Sent when the length has changed
47*0b05c6eaSNicolas Bonnefon     void lengthChanged();
48*0b05c6eaSNicolas Bonnefon     // Sent when the hooked status has changed
49*0b05c6eaSNicolas Bonnefon     void hooked( bool is_hooked );
50*0b05c6eaSNicolas Bonnefon 
51*0b05c6eaSNicolas Bonnefon   private:
52*0b05c6eaSNicolas Bonnefon     static constexpr int TIMER_PERIOD_MS = 10;
53*0b05c6eaSNicolas Bonnefon     static constexpr int DECREASE_RATE = 2;
54*0b05c6eaSNicolas Bonnefon     int hook_threshold_;
55*0b05c6eaSNicolas Bonnefon     int position_ = 0;
56*0b05c6eaSNicolas Bonnefon     int timer_id_ = 0;
57*0b05c6eaSNicolas Bonnefon };
58*0b05c6eaSNicolas Bonnefon 
59*0b05c6eaSNicolas Bonnefon #endif
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