pv/widgets/popup.cpp

   1 /*
   2  * This file is part of the PulseView project.
   3  *
   4  * Copyright (C) 2013 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 <algorithm>
  21 #include <cassert>
  22
  23 #include <QApplication>
  24 #include <QDesktopWidget>
  25 #include <QLineEdit>
  26 #include <QScrollBar>
  27 #include <QStyle>
  28 #include <QtGui>
  29
  30 #include "popup.hpp"
  31
  32 using std::max;
  33 using std::min;
  34
  35 namespace pv {
  36 namespace widgets {
  37
  38 const unsigned int Popup::ArrowLength = 10;
  39 const unsigned int Popup::ArrowOverlap = 3;
  40 const unsigned int Popup::MarginWidth = 6;
  41
  42
  43 QWidthAdjustingScrollArea::QWidthAdjustingScrollArea(QWidget* parent) :
  44         QScrollArea(parent)
  45 {
  46 }
  47
  48 void QWidthAdjustingScrollArea::setWidget(QWidget* w)
  49 {
  50         QScrollArea::setWidget(w);
  51         // It happens that QScrollArea already filters widget events,
  52         // but that's an implementation detail that we shouldn't rely on.
  53         w->installEventFilter(this);
  54 }
  55
  56 bool QWidthAdjustingScrollArea::eventFilter(QObject* obj, QEvent* ev)
  57 {
  58         if (obj == widget() && ev->type() == QEvent::Resize) {
  59                 if (widget()->height() > height())
  60                         setMinimumWidth(widget()->width() + qApp->style()->pixelMetric(QStyle::PM_ScrollBarExtent));
  61                 else
  62                         setMinimumWidth(widget()->width());
  63         }
  64
  65         return QScrollArea::eventFilter(obj, ev);
  66 }
  67
  68
  69 Popup::Popup(QWidget *parent) :
  70         QWidget(parent, Qt::Popup | Qt::FramelessWindowHint),
  71         point_(),
  72         pos_(Left)
  73 {
  74 }
  75
  76 const QPoint& Popup::point() const
  77 {
  78         return point_;
  79 }
  80
  81 Popup::Position Popup::position() const
  82 {
  83         return pos_;
  84 }
  85
  86 void Popup::set_position(const QPoint point, Position pos)
  87 {
  88         point_ = point, pos_ = pos;
  89
  90         setContentsMargins(
  91                 MarginWidth + ((pos == Right) ? ArrowLength : 0),
  92                 MarginWidth + ((pos == Bottom) ? ArrowLength : 0),
  93                 MarginWidth + ((pos == Left) ? ArrowLength : 0),
  94                 MarginWidth + ((pos == Top) ? ArrowLength : 0));
  95 }
  96
  97 bool Popup::eventFilter(QObject *obj, QEvent *event)
  98 {
  99         QKeyEvent *keyEvent;
 100
 101         (void)obj;
 102
 103         if (event->type() == QEvent::KeyPress) {
 104                 keyEvent = static_cast<QKeyEvent*>(event);
 105                 if (keyEvent->key() == Qt::Key_Enter ||
 106                     keyEvent->key() == Qt::Key_Return) {
 107                         close();
 108                         return true;
 109                 }
 110         }
 111
 112         return false;
 113 }
 114
 115 void Popup::show()
 116 {
 117         QLineEdit* le;
 118
 119         QWidget::show();
 120
 121         // We want to close the popup when the Enter key was
 122         // pressed and the first editable widget had focus.
 123         if ((le = this->findChild<QLineEdit*>())) {
 124
 125                 // For combo boxes we need to hook into the parent of
 126                 // the line edit (i.e. the QComboBox). For edit boxes
 127                 // we hook into the widget directly.
 128                 if (le->parent()->metaObject()->className() ==
 129                                 this->metaObject()->className())
 130                         le->installEventFilter(this);
 131                 else
 132                         le->parent()->installEventFilter(this);
 133
 134                 le->selectAll();
 135                 le->setFocus();
 136         }
 137 }
 138
 139 bool Popup::space_for_arrow() const
 140 {
 141         // Check if there is room for the arrow
 142         switch (pos_) {
 143         case Right:
 144                 if (point_.x() > x())
 145                         return false;
 146                 return true;
 147
 148         case Bottom:
 149                 if (point_.y() > y())
 150                         return false;
 151                 return true;
 152
 153         case Left:
 154                 if (point_.x() < (x() + width()))
 155                         return false;
 156                 return true;
 157
 158         case Top:
 159                 if (point_.y() < (y() + height()))
 160                         return false;
 161                 return true;
 162         }
 163
 164         return true;
 165 }
 166
 167 QPolygon Popup::arrow_polygon() const
 168 {
 169         QPolygon poly;
 170
 171         const QPoint p = mapFromGlobal(point_);
 172         const int l = ArrowLength + ArrowOverlap;
 173
 174         switch (pos_) {
 175         case Right:
 176                 poly << QPoint(p.x() + l, p.y() - l);
 177                 break;
 178
 179         case Bottom:
 180                 poly << QPoint(p.x() - l, p.y() + l);
 181                 break;
 182
 183         case Left:
 184         case Top:
 185                 poly << QPoint(p.x() - l, p.y() - l);
 186                 break;
 187         }
 188
 189         poly << p;
 190
 191         switch (pos_) {
 192         case Right:
 193         case Bottom:
 194                 poly << QPoint(p.x() + l, p.y() + l);
 195                 break;
 196
 197         case Left:
 198                 poly << QPoint(p.x() - l, p.y() + l);
 199                 break;
 200
 201         case Top:
 202                 poly << QPoint(p.x() + l, p.y() - l);
 203                 break;
 204         }
 205
 206         return poly;
 207 }
 208
 209 QRegion Popup::arrow_region() const
 210 {
 211         return QRegion(arrow_polygon());
 212 }
 213
 214 QRect Popup::bubble_rect() const
 215 {
 216         return QRect(
 217                 QPoint((pos_ == Right) ? ArrowLength : 0,
 218                         (pos_ == Bottom) ? ArrowLength : 0),
 219                 QSize(width() - ((pos_ == Left || pos_ == Right) ?
 220                                 ArrowLength : 0),
 221                         height() - ((pos_ == Top || pos_ == Bottom) ?
 222                                 ArrowLength : 0)));
 223 }
 224
 225 QRegion Popup::bubble_region() const
 226 {
 227         const QRect rect(bubble_rect());
 228
 229         const unsigned int r = MarginWidth;
 230         const unsigned int d = 2 * r;
 231         return QRegion(rect.adjusted(r, 0, -r, 0)).united(
 232                 QRegion(rect.adjusted(0, r, 0, -r))).united(
 233                 QRegion(rect.left(), rect.top(), d, d,
 234                         QRegion::Ellipse)).united(
 235                 QRegion(rect.right() - d, rect.top(), d, d,
 236                         QRegion::Ellipse)).united(
 237                 QRegion(rect.left(), rect.bottom() - d, d, d,
 238                         QRegion::Ellipse)).united(
 239                 QRegion(rect.right() - d, rect.bottom() - d, d, d,
 240                         QRegion::Ellipse));
 241 }
 242
 243 QRegion Popup::popup_region() const
 244 {
 245         if (space_for_arrow())
 246                 return arrow_region().united(bubble_region());
 247         else
 248                 return bubble_region();
 249 }
 250
 251 void Popup::reposition_widget()
 252 {
 253         QPoint o;
 254
 255         const QRect screen_rect = QApplication::desktop()->availableGeometry(
 256                 QApplication::desktop()->screenNumber(point_));
 257
 258         if (pos_ == Right || pos_ == Left)
 259                 o.ry() = -height() / 2;
 260         else
 261                 o.rx() = -width() / 2;
 262
 263         if (pos_ == Left)
 264                 o.rx() = -width();
 265         else if (pos_ == Top)
 266                 o.ry() = -height();
 267
 268         o += point_;
 269         move(max(min(o.x(), screen_rect.right() - width()),
 270                         screen_rect.left()),
 271                 max(min(o.y(), screen_rect.bottom() - height()),
 272                         screen_rect.top()));
 273 }
 274
 275 void Popup::closeEvent(QCloseEvent*)
 276 {
 277         closed();
 278 }
 279
 280 void Popup::paintEvent(QPaintEvent*)
 281 {
 282         QPainter painter(this);
 283         painter.setRenderHint(QPainter::Antialiasing);
 284
 285         const QColor outline_color(QApplication::palette().color(
 286                 QPalette::Dark));
 287
 288         // Draw the bubble
 289         const QRegion b = bubble_region();
 290         const QRegion bubble_outline = QRegion(rect()).subtracted(
 291                 b.translated(1, 0).intersected(b.translated(0, 1).intersected(
 292                 b.translated(-1, 0).intersected(b.translated(0, -1)))));
 293
 294         painter.setPen(Qt::NoPen);
 295         painter.setBrush(QApplication::palette().brush(QPalette::Window));
 296         painter.drawRect(rect());
 297
 298         // Draw the arrow
 299         if (!space_for_arrow())
 300                 return;
 301
 302         const QPoint ArrowOffsets[] = {
 303                 QPoint(1, 0), QPoint(0, -1), QPoint(-1, 0), QPoint(0, 1)};
 304
 305         const QRegion a(arrow_region());
 306         const QRegion arrow_outline = a.subtracted(
 307                 a.translated(ArrowOffsets[pos_]));
 308
 309         painter.setClipRegion(bubble_outline.subtracted(a).united(
 310                 arrow_outline));
 311         painter.setBrush(outline_color);
 312         painter.drawRect(rect());
 313 }
 314
 315 void Popup::resizeEvent(QResizeEvent*)
 316 {
 317         reposition_widget();
 318         setMask(popup_region());
 319 }
 320
 321 void Popup::mouseReleaseEvent(QMouseEvent *event)
 322 {
 323         assert(event);
 324
 325         // We need our own out-of-bounds click handler because QWidget counts
 326         // the drop-shadow region as inside the widget
 327         if (!bubble_rect().contains(event->pos()))
 328                 close();
 329 }
 330
 331 void Popup::showEvent(QShowEvent*)
 332 {
 333         reposition_widget();
 334 }
 335
 336 } // namespace widgets
 337 } // namespace pv