pv/view/ruler.cpp

   1 /*
   2  * This file is part of the PulseView project.
   3  *
   4  * Copyright (C) 2012 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, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #include "ruler.h"
  22
  23 #include "cursor.h"
  24 #include "view.h"
  25 #include "viewport.h"
  26
  27 #include <extdef.h>
  28
  29 #include <assert.h>
  30 #include <math.h>
  31
  32 #include <QMouseEvent>
  33 #include <QPainter>
  34 #include <QTextStream>
  35
  36 using namespace std;
  37
  38 namespace pv {
  39 namespace view {
  40
  41 const int Ruler::MinorTickSubdivision = 4;
  42 const int Ruler::ScaleUnits[3] = {1, 2, 5};
  43
  44 const QString Ruler::SIPrefixes[9] =
  45         {"f", "p", "n", QChar(0x03BC), "m", "", "k", "M", "G"};
  46 const int Ruler::FirstSIPrefixPower = -15;
  47
  48 const int Ruler::HoverArrowSize = 5;
  49
  50 Ruler::Ruler(View &parent) :
  51         QWidget(&parent),
  52         _view(parent),
  53         _grabbed_marker(NULL)
  54 {
  55         setMouseTracking(true);
  56
  57         connect(&_view, SIGNAL(hover_point_changed()),
  58                 this, SLOT(hover_point_changed()));
  59 }
  60
  61 void Ruler::paintEvent(QPaintEvent *event)
  62 {
  63         QPainter p(this);
  64         p.setRenderHint(QPainter::Antialiasing);
  65
  66         const double MinSpacing = 80;
  67
  68         const double min_period = _view.scale() * MinSpacing;
  69
  70         const int order = (int)floorf(log10f(min_period));
  71         const double order_decimal = pow(10, order);
  72
  73         unsigned int unit = 0;
  74         double tick_period = 0.0f;
  75
  76         do
  77         {
  78                 tick_period = order_decimal * ScaleUnits[unit++];
  79         } while (tick_period < min_period && unit < countof(ScaleUnits));
  80
  81         const unsigned int prefix = (order - FirstSIPrefixPower) / 3;
  82         assert(prefix < countof(SIPrefixes));
  83
  84         const double multiplier = pow(10.0, - prefix * 3 - FirstSIPrefixPower);
  85
  86         const int text_height = p.boundingRect(0, 0, INT_MAX, INT_MAX,
  87                 Qt::AlignLeft | Qt::AlignTop, "8").height();
  88
  89         // Draw the tick marks
  90         p.setPen(Qt::black);
  91
  92         const double minor_tick_period = tick_period / MinorTickSubdivision;
  93         const double first_major_division =
  94                 floor(_view.offset() / tick_period);
  95         const double first_minor_division =
  96                 ceil(_view.offset() / minor_tick_period);
  97         const double t0 = first_major_division * tick_period;
  98
  99         int division = (int)round(first_minor_division -
 100                 first_major_division * MinorTickSubdivision);
 101         while (1)
 102         {
 103                 const double t = t0 + division * minor_tick_period;
 104                 const double x = (t - _view.offset()) / _view.scale();
 105
 106                 if (x >= width())
 107                         break;
 108
 109                 if (division % MinorTickSubdivision == 0)
 110                 {
 111                         // Draw a major tick
 112                         QString s;
 113                         QTextStream ts(&s);
 114                         ts << (t * multiplier) << SIPrefixes[prefix] << "s";
 115                         p.drawText(x, 0, 0, text_height, Qt::AlignCenter |
 116                                 Qt::AlignTop | Qt::TextDontClip, s);
 117                         p.drawLine(QPointF(x, text_height),
 118                                 QPointF(x, height()));
 119                 }
 120                 else
 121                 {
 122                         // Draw a minor tick
 123                         p.drawLine(QPointF(x, (text_height + height()) / 2),
 124                                 QPointF(x, height()));
 125                 }
 126
 127                 division++;
 128         }
 129
 130         // Draw the cursors
 131         draw_cursors(p);
 132
 133         // Draw the hover mark
 134         draw_hover_mark(p);
 135
 136         p.end();
 137 }
 138
 139 void Ruler::mouseMoveEvent(QMouseEvent *e)
 140 {
 141         if (!_grabbed_marker)
 142                 return;
 143
 144         _grabbed_marker->set_time(_view.offset() +
 145                 ((double)e->x() + 0.5) * _view.scale());
 146 }
 147
 148 void Ruler::mousePressEvent(QMouseEvent *e)
 149 {
 150         if (e->buttons() & Qt::LeftButton) {
 151                 _grabbed_marker = NULL;
 152
 153                 if (_view.cursors_shown()) {
 154                         std::pair<Cursor, Cursor> &cursors =
 155                                 _view.cursors();
 156                         if (cursors.first.get_label_rect(
 157                                 rect()).contains(e->pos()))
 158                                 _grabbed_marker = &cursors.first;
 159                         else if (cursors.second.get_label_rect(
 160                                 rect()).contains(e->pos()))
 161                                 _grabbed_marker = &cursors.second;
 162                 }
 163         }
 164 }
 165
 166 void Ruler::mouseReleaseEvent(QMouseEvent *)
 167 {
 168         _grabbed_marker = NULL;
 169 }
 170
 171 void Ruler::draw_cursors(QPainter &p)
 172 {
 173         if (!_view.cursors_shown())
 174                 return;
 175
 176         const QRect r = rect();
 177         pair<Cursor, Cursor> &cursors = _view.cursors();
 178         cursors.first.paint_label(p, r);
 179         cursors.second.paint_label(p, r);
 180 }
 181
 182 void Ruler::draw_hover_mark(QPainter &p)
 183 {
 184         const int x = _view.hover_point().x();
 185
 186         if (x == -1 || _grabbed_marker)
 187                 return;
 188
 189         p.setPen(QPen(Qt::NoPen));
 190         p.setBrush(QBrush(QColor(Qt::black)));
 191
 192         const int b = height() - 1;
 193         const QPointF points[] = {
 194                 QPointF(x, b),
 195                 QPointF(x - HoverArrowSize, b - HoverArrowSize),
 196                 QPointF(x + HoverArrowSize, b - HoverArrowSize)
 197         };
 198         p.drawPolygon(points, countof(points));
 199 }
 200
 201 void Ruler::hover_point_changed()
 202 {
 203         update();
 204 }
 205
 206 } // namespace view
 207 } // namespace pv