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