1 | #include <qstyle.h>
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2 | #include <qstyleoption.h>
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3 | #include "Scrollbar.h"
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4 |
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5 | ScrollBar::ScrollBar(QWidget * parent):
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6 | QScrollBar(parent)
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7 | {
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8 | init();
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9 | }
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10 |
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11 | ScrollBar::ScrollBar(Qt::Orientation o,
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12 | QWidget *parent):
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13 | QScrollBar(o, parent)
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14 | {
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15 | init();
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16 | }
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17 |
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18 | ScrollBar::ScrollBar(float minBase, float maxBase,
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19 | Qt::Orientation o, QWidget *parent):
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20 | QScrollBar(o, parent)
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21 | {
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22 | init();
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23 | setBase(minBase, maxBase);
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24 | moveSlider(minBase, maxBase);
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25 | }
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26 |
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27 | void ScrollBar::init(void)
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28 | {
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29 | d_inverted = orientation() == Qt::Vertical;
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30 | d_baseTicks = 1000000;
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31 | d_minBase = 0.0;
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32 | d_maxBase = 1.0;
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33 | moveSlider(d_minBase, d_maxBase);
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34 |
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35 | connect(this, SIGNAL(sliderMoved(int)), SLOT(catchSliderMoved(int)));
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36 | connect(this, SIGNAL(valueChanged(int)), SLOT(catchValueChanged(int)));
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37 | }
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38 |
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39 | void ScrollBar::setInverted(bool inverted)
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40 | {
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41 | if ( d_inverted != inverted )
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42 | {
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43 | d_inverted = inverted;
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44 | moveSlider(minSliderValue(), maxSliderValue());
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45 | }
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46 | }
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47 |
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48 | bool ScrollBar::isInverted(void) const
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49 | {
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50 | return d_inverted;
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51 | }
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52 |
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53 | void ScrollBar::setBase(float min, float max)
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54 | {
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55 | if ( min != d_minBase || max != d_maxBase )
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56 | {
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57 | d_minBase = min;
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58 | d_maxBase = max;
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59 |
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60 | moveSlider(minSliderValue(), maxSliderValue());
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61 | }
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62 | }
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63 |
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64 | void ScrollBar::moveSlider(float min, float max)
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65 | {
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66 | const int sliderTicks = qRound((max - min) /
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67 | (d_maxBase - d_minBase) * d_baseTicks);
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68 |
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69 | // setRange initiates a valueChanged of the scrollbars
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70 | // in some situations. So we block
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71 | // and unblock the signals.
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72 |
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73 | blockSignals(true);
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74 |
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75 | setRange(sliderTicks / 2, d_baseTicks - sliderTicks / 2);
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76 | int steps = sliderTicks / 200;
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77 | if ( steps <= 0 )
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78 | steps = 1;
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79 |
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80 | setSingleStep(steps);
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81 | setPageStep(sliderTicks);
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82 |
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83 | int tick = mapToTick(min + (max - min) / 2);
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84 | if ( isInverted() )
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85 | tick = d_baseTicks - tick;
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86 |
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87 | setSliderPosition(tick);
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88 | blockSignals(false);
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89 | }
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90 |
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91 | float ScrollBar::minBaseValue(void) const
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92 | {
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93 | return d_minBase;
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94 | }
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95 |
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96 | float ScrollBar::maxBaseValue(void) const
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97 | {
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98 | return d_maxBase;
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99 | }
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100 |
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101 | void ScrollBar::sliderRange(int value, float &min, float &max) const
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102 | {
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103 | if ( isInverted() )
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104 | value = d_baseTicks - value;
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105 |
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106 | const int visibleTicks = pageStep();
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107 |
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108 | min = mapFromTick(value - visibleTicks / 2);
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109 | max = mapFromTick(value + visibleTicks / 2);
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110 | }
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111 |
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112 | float ScrollBar::minSliderValue(void) const
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113 | {
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114 | float min, dummy;
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115 | sliderRange(value(), min, dummy);
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116 |
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117 | return min;
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118 | }
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119 |
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120 | float ScrollBar::maxSliderValue(void) const
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121 | {
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122 | float max, dummy;
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123 | sliderRange(value(), dummy, max);
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124 |
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125 | return max;
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126 | }
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127 |
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128 | int ScrollBar::mapToTick(float v) const
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129 | {
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130 | return (int) ( ( v - d_minBase) / (d_maxBase - d_minBase ) * d_baseTicks );
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131 | }
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132 |
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133 | float ScrollBar::mapFromTick(int tick) const
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134 | {
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135 | return d_minBase + ( d_maxBase - d_minBase ) * tick / d_baseTicks;
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136 | }
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137 |
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138 | void ScrollBar::catchValueChanged(int value)
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139 | {
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140 | float min, max;
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141 | sliderRange(value, min, max);
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142 | Q_EMIT valueChanged(orientation(), min, max);
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143 | }
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144 |
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145 | void ScrollBar::catchSliderMoved(int value)
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146 | {
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147 | float min, max;
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148 | sliderRange(value, min, max);
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149 | Q_EMIT sliderMoved(orientation(), min, max);
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150 | }
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151 |
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152 | int ScrollBar::extent(void) const
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153 | {
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154 | QStyleOptionSlider opt;
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155 | opt.init(this);
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156 | opt.subControls = QStyle::SC_None;
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157 | opt.activeSubControls = QStyle::SC_None;
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158 | opt.orientation = orientation();
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159 | opt.minimum = minimum();
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160 | opt.maximum = maximum();
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161 | opt.sliderPosition = sliderPosition();
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162 | opt.sliderValue = value();
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163 | opt.singleStep = singleStep();
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164 | opt.pageStep = pageStep();
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165 | opt.upsideDown = invertedAppearance();
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166 | if (orientation() == Qt::Horizontal)
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167 | opt.state |= QStyle::State_Horizontal;
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168 | return style()->pixelMetric(QStyle::PM_ScrollBarExtent, &opt, this);
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169 | }
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