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