Trace view: Allow setting cursors via shift-drag
[pulseview.git] / pv / views / trace / viewwidget.cpp
1 /*
2  * This file is part of the PulseView project.
3  *
4  * Copyright (C) 2014 Joel Holdsworth <joel@airwebreathe.org.uk>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19
20 #include <QApplication>
21 #include <QMouseEvent>
22 #include <QTouchEvent>
23
24 #include "tracetreeitem.hpp"
25 #include "view.hpp"
26 #include "viewwidget.hpp"
27
28 using std::any_of;
29 using std::shared_ptr;
30 using std::vector;
31
32 namespace pv {
33 namespace views {
34 namespace trace {
35
36 ViewWidget::ViewWidget(View &parent) :
37         QWidget(&parent),
38         view_(parent),
39         item_dragging_(false)
40 {
41         setFocusPolicy(Qt::ClickFocus);
42         setAttribute(Qt::WA_AcceptTouchEvents, true);
43         setMouseTracking(true);
44 }
45
46 void ViewWidget::clear_selection()
47 {
48         const auto items = this->items();
49         for (auto &i : items)
50                 i->select(false);
51 }
52
53 void ViewWidget::item_hover(const shared_ptr<ViewItem> &item, QPoint pos)
54 {
55         (void)item;
56         (void)pos;
57 }
58
59 void ViewWidget::item_clicked(const shared_ptr<ViewItem> &item)
60 {
61         (void)item;
62 }
63
64 bool ViewWidget::accept_drag() const
65 {
66         const vector< shared_ptr<TimeItem> > items(view_.time_items());
67         const vector< shared_ptr<TraceTreeItem> > trace_tree_items(
68                 view_.list_by_type<TraceTreeItem>());
69
70         const bool any_row_items_selected = any_of(
71                 trace_tree_items.begin(), trace_tree_items.end(),
72                 [](const shared_ptr<TraceTreeItem> &r) { return r->selected(); });
73
74         const bool any_time_items_selected = any_of(items.begin(), items.end(),
75                 [](const shared_ptr<TimeItem> &i) { return i->selected(); });
76
77         if (any_row_items_selected && !any_time_items_selected) {
78                 // Check all the drag items share a common owner
79                 TraceTreeItemOwner *item_owner = nullptr;
80                 for (const shared_ptr<TraceTreeItem>& r : trace_tree_items)
81                         if (r->dragging()) {
82                                 if (!item_owner)
83                                         item_owner = r->owner();
84                                 else if (item_owner != r->owner())
85                                         return false;
86                         }
87
88                 return true;
89         } else if (any_time_items_selected && !any_row_items_selected) {
90                 return true;
91         }
92
93         // A background drag is beginning
94         return true;
95 }
96
97 bool ViewWidget::mouse_down() const
98 {
99         return mouse_down_point_.x() != INT_MIN &&
100                 mouse_down_point_.y() != INT_MIN;
101 }
102
103 void ViewWidget::drag_items(const QPoint &delta)
104 {
105         bool item_dragged = false;
106
107         // Drag the row items
108         const vector< shared_ptr<ViewItem> > row_items(
109                 view_.list_by_type<ViewItem>());
110         for (const shared_ptr<ViewItem>& r : row_items)
111                 if (r->dragging()) {
112                         r->drag_by(delta);
113
114                         // Ensure the trace is selected
115                         r->select();
116
117                         item_dragged = true;
118                 }
119
120         // If an item is being dragged, update the stacking
121         TraceTreeItemOwner *item_owner = nullptr;
122         const vector< shared_ptr<TraceTreeItem> > trace_tree_items(
123                 view_.list_by_type<TraceTreeItem>());
124         for (const shared_ptr<TraceTreeItem>& i : trace_tree_items)
125                 if (i->dragging())
126                         item_owner = i->owner();
127
128         if (item_owner) {
129                 item_owner->restack_items();
130                 for (shared_ptr<TraceTreeItem> i : trace_tree_items)
131                         i->animate_to_layout_v_offset();
132         }
133
134         // Drag the time items
135         const vector< shared_ptr<TimeItem> > items(view_.time_items());
136         for (auto &i : items)
137                 if (i->dragging()) {
138                         i->drag_by(delta);
139                         item_dragged = true;
140                 }
141
142         // Do the background drag
143         if (!item_dragged)
144                 drag_by(delta);
145 }
146
147 void ViewWidget::drag()
148 {
149 }
150
151 void ViewWidget::drag_by(const QPoint &delta)
152 {
153         (void)delta;
154 }
155
156 void ViewWidget::drag_release()
157 {
158 }
159
160 void ViewWidget::mouse_left_press_event(QMouseEvent *event)
161 {
162         (void)event;
163
164         const bool ctrl_pressed =
165                 QApplication::keyboardModifiers() & Qt::ControlModifier;
166
167         // Clear selection if control is not pressed and this item is unselected
168         if ((!mouse_down_item_ || !mouse_down_item_->selected()) &&
169                 !ctrl_pressed)
170                 clear_selection();
171
172         // Set the signal selection state if the item has been clicked
173         if (mouse_down_item_ && mouse_down_item_->is_selectable(event->pos())) {
174                 if (ctrl_pressed)
175                         mouse_down_item_->select(!mouse_down_item_->selected());
176                 else
177                         mouse_down_item_->select(true);
178         }
179
180         // Save the offsets of any signals which will be dragged
181         bool item_dragged = false;
182         const auto items = this->items();
183         for (auto &i : items)
184                 if (i->selected() && i->is_draggable(event->pos())) {
185                         item_dragged = true;
186                         i->drag();
187                 }
188
189         // Do the background drag
190         if (!item_dragged)
191                 drag();
192
193         selection_changed();
194 }
195
196 void ViewWidget::mouse_left_release_event(QMouseEvent *event)
197 {
198         assert(event);
199
200         auto items = this->items();
201         const bool ctrl_pressed =
202                 QApplication::keyboardModifiers() & Qt::ControlModifier;
203
204         // Unselect everything if control is not pressed
205         const shared_ptr<ViewItem> mouse_over =
206                 get_mouse_over_item(event->pos());
207
208         for (auto &i : items)
209                 i->drag_release();
210
211         if (item_dragging_)
212                 view_.restack_all_trace_tree_items();
213         else {
214                 if (!ctrl_pressed) {
215                         for (shared_ptr<ViewItem> i : items)
216                                 if (mouse_down_item_ != i)
217                                         i->select(false);
218
219                         if (mouse_down_item_)
220                                 item_clicked(mouse_down_item_);
221                 }
222         }
223
224         item_dragging_ = false;
225 }
226
227 bool ViewWidget::touch_event(QTouchEvent *event)
228 {
229         (void)event;
230
231         return false;
232 }
233
234 bool ViewWidget::event(QEvent *event)
235 {
236         switch (event->type()) {
237         case QEvent::TouchBegin:
238         case QEvent::TouchUpdate:
239         case QEvent::TouchEnd:
240                 if (touch_event(static_cast<QTouchEvent *>(event)))
241                         return true;
242                 break;
243
244         default:
245                 break;
246         }
247
248         return QWidget::event(event);
249 }
250
251 void ViewWidget::mousePressEvent(QMouseEvent *event)
252 {
253         assert(event);
254
255         if (event->button() & Qt::LeftButton) {
256         if (event->modifiers() & Qt::ShiftModifier)
257             view_.show_cursors(false);
258                 mouse_down_point_ = event->pos();
259                 mouse_down_offset_ =  view_.offset() + event->pos().x() * view_.scale();
260                 mouse_down_item_ = get_mouse_over_item(event->pos());
261                 mouse_left_press_event(event);
262         }
263
264         /* Don't forward right click events as they will open context menus when
265          * used on trace labels. Those menus prevent ViewWidget::mouseReleaseEvent()
266          * to be triggered upon button release, making mouse_down_item_
267          * hold the last reference to a view item that might have been deleted
268          * from the context menu, preventing it from being freed as intended.
269          * TODO Remove this once context menus are handled separately
270          */
271         if (event->button() & Qt::RightButton)
272                 mouse_down_point_ = event->pos();
273 }
274
275 void ViewWidget::mouseReleaseEvent(QMouseEvent *event)
276 {
277         assert(event);
278
279         if (event->button() & Qt::LeftButton)
280                 mouse_left_release_event(event);
281
282         mouse_down_point_ = QPoint(INT_MIN, INT_MIN);
283         mouse_down_item_ = nullptr;
284 }
285
286 void ViewWidget::mouseMoveEvent(QMouseEvent *event)
287 {
288         assert(event);
289         mouse_point_ = event->pos();
290
291         if (!event->buttons()) {
292                 item_hover(get_mouse_over_item(event->pos()), event->pos());
293
294     } else if (event->buttons() & Qt::LeftButton) {
295
296         if (event->modifiers() & Qt::ShiftModifier) { // Cursor drag 
297             pv::util::Timestamp current_offset =  view_.offset() + event->pos().x() * view_.scale();
298
299             // TODO: Is startDragDistance the right constant here?
300             if (qAbs(current_offset - mouse_down_offset_)/view_.scale() > QApplication::startDragDistance()) {
301                 view_.show_cursors(true);
302                 view_.set_cursors(mouse_down_offset_, current_offset);
303
304             } else {
305                 view_.show_cursors(false);
306             }
307
308         } else {
309             if (!item_dragging_) {
310                 if ((event->pos() - mouse_down_point_).manhattanLength() <
311                     QApplication::startDragDistance())
312                     return;
313
314                 if (!accept_drag())
315                     return;
316
317                 item_dragging_ = true;
318             }
319
320             // Do the drag
321             drag_items(event->pos() - mouse_down_point_);
322         }
323         }
324 }
325
326 void ViewWidget::leaveEvent(QEvent*)
327 {
328         mouse_point_ = QPoint(-1, -1);
329         update();
330 }
331
332 } // namespace trace
333 } // namespace views
334 } // namespace pv