ground/gcs/src/libs/utils/textbubbleslider.cpp

   1 /**
   2  ******************************************************************************
   3  *
   4  * @file       textbubbleslider.h
   5  * @author     Tau Labs, http://taulabs.org Copyright (C) 2013.
   6  * @brief      Creates a slider with a text bubble showing the slider value
   7  * @see        The GNU Public License (GPL) Version 3
   8  * @defgroup
   9  * @{
  10  *
  11  *****************************************************************************/
  12 /*
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 3 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful, but
  19  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  20  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  21  * for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License along
  24  * with this program; if not, write to the Free Software Foundation, Inc.,
  25  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  26  */
  27
  28 #include <QDebug>
  29 #include <QPainter>
  30 #include <QtGui>
  31 #include <qmath.h>
  32
  33 #include "textbubbleslider.h"
  34
  35 /**
  36  * @brief TextBubbleSlider::TextBubbleSlider Constructs a regular text-bubble slider
  37  * @param parent
  38  */
  39 TextBubbleSlider::TextBubbleSlider(QWidget *parent) :
  40     QSlider(parent)
  41 {
  42     QFontDatabase::addApplicationFont(":/utils/fonts/PTS75F.ttf");
  43
  44     construct();
  45 }
  46
  47 /**
  48  * @brief TextBubbleSlider::TextBubbleSlider Constructs a text-bubble slider that copys
  49  * all relevant data from the previous slider
  50  * @param copySlider
  51  * @param parent
  52  */
  53 TextBubbleSlider::TextBubbleSlider(QSlider *copySlider, QWidget *parent) :
  54     QSlider(parent)
  55 {
  56     construct();
  57
  58     // Copy settings
  59     setSizePolicy(copySlider->sizePolicy());
  60     setMinimumSize(copySlider->minimumSize());
  61     setMaximumSize(copySlider->maximumSize());
  62     setFocusPolicy(copySlider->focusPolicy());
  63     setOrientation(copySlider->orientation());
  64     setMaximum(copySlider->maximum());
  65     setMinimum(copySlider->minimum());
  66     setToolTip(copySlider->toolTip());
  67 }
  68
  69
  70 /**
  71  * @brief TextBubbleSlider::construct This function needs to be called from all constructors. It
  72  * provides a single point where settings can be changed.
  73  */
  74 void TextBubbleSlider::construct()
  75 {
  76     font = QFont("PT Sans", 13, QFont::Bold);
  77     slideHandleMargin = 2; // This is a dubious way to set the margin. In reality, it should be read from the style sheet.
  78 }
  79
  80 TextBubbleSlider::~TextBubbleSlider()
  81 {}
  82
  83
  84 /**
  85  * @brief numIntegerDigits Counts the number of digits in an integer
  86  * @param number Input integer
  87  * @return Number of digits in input integer
  88  */
  89 unsigned int numIntegerDigits(int number)
  90 {
  91     unsigned int digits = 0;
  92
  93     // If there is a negative sign, be sure to include it in digit count
  94     if (number < 0) {
  95         digits = 1;
  96     }
  97
  98     while (number) {
  99         number /= 10;
 100         digits++;
 101     }
 102
 103     return digits;
 104 }
 105
 106
 107 /**
 108  * @brief TextBubbleSlider::setMaxPixelWidth Sets maximum pixel width for slider handle
 109  */
 110 void TextBubbleSlider::setMaxPixelWidth()
 111 {
 112     // Calculate maximum number of digits possible in string
 113     int maxNumDigits = numIntegerDigits(maximum()) > numIntegerDigits(minimum()) ? numIntegerDigits(maximum()) : numIntegerDigits(minimum());
 114
 115     // Generate string with maximum pixel width. Suppose that "0" is
 116     // the widest number in pixels.
 117     QString maximumWidthString;
 118
 119     for (int i = 0; i < maxNumDigits; i++) {
 120         maximumWidthString.append("0");
 121     }
 122
 123     // Calculate maximum possible pixel width for string.
 124     QFontMetrics fontMetrics(font);
 125     maximumFontWidth  = fontMetrics.width(QString("%1").arg(maximumWidthString));
 126     maximumFontHeight = fontMetrics.height();
 127
 128     // Override stylesheet slider handle width
 129     slideHandleWidth  = maximumFontWidth + 6;
 130     setStyleSheet(QString("QSlider::handle:horizontal { width: %1px; margin: -5px 0;}").arg(slideHandleWidth));
 131 }
 132
 133
 134 /**
 135  * @brief TextBubbleSlider::setMinimum Reimplements setMinimum. Ensures that the slider
 136  * handle is the correct size for the text field.
 137  * @param max maximum
 138  */
 139 void TextBubbleSlider::setMinimum(int max)
 140 {
 141     // Pass value on to QSlider
 142     QSlider::setMinimum(max);
 143
 144     // Reset handler size
 145     setMaxPixelWidth();
 146 }
 147
 148
 149 /**
 150  * @brief TextBubbleSlider::setMaximum Reimplements setMaximum. Ensures that the slider
 151  * handle is the correct size for the text field.
 152  * @param max maximum
 153  */
 154 void TextBubbleSlider::setMaximum(int max)
 155 {
 156     // Pass value on to QSlider
 157     QSlider::setMaximum(max);
 158
 159     // Reset handler size
 160     setMaxPixelWidth();
 161 }
 162
 163
 164 /**
 165  * @brief TextBubbleSlider::paintEvent Reimplements QSlider::paintEvent.
 166  * @param bob
 167  */
 168 void TextBubbleSlider::paintEvent(QPaintEvent *paintEvent)
 169 {
 170     // Pass paint event on to QSlider
 171     QSlider::paintEvent(paintEvent);
 172
 173     /* Add numbers on top of handler */
 174
 175     // Calculate pixel position for text.
 176     int sliderWidth  = width();
 177     int sliderHeight = height();
 178     double valuePos;
 179
 180     if (!invertedAppearance()) {
 181         valuePos = (slideHandleWidth - maximumFontWidth) / 2 + slideHandleMargin + // First part centers text in handle...
 182                    (value() - minimum()) / (double)(maximum() - minimum()) * (sliderWidth - (slideHandleWidth + slideHandleMargin) - 1); // ... and second part moves text with handle
 183     } else {
 184         valuePos = (slideHandleWidth - maximumFontWidth) / 2 + slideHandleMargin + // First part centers text in handle...
 185                    (maximum() - value()) / (double)(maximum() - minimum()) * (sliderWidth - (slideHandleWidth + slideHandleMargin) - 1); // ... and second part moves text with handle
 186     }
 187
 188     // Create painter and set font
 189     QPainter painter(this);
 190     painter.setFont(font);
 191     painter.setPen(QPen(QColor(80, 80, 80)));
 192
 193     // Draw neutral value text. Vertically center it in the handle
 194     QString neutralStringWidth = QString("%1").arg(value());
 195     QFontMetrics fontMetrics(font);
 196     int textWidth = fontMetrics.width(neutralStringWidth);
 197     painter.drawText(QRectF(valuePos + maximumFontWidth - textWidth, ceil((sliderHeight - maximumFontHeight) / 2.0), textWidth, maximumFontHeight),
 198                      neutralStringWidth);
 199 }