1 | # -*- coding: utf-8 -*- |
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2 | |
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3 | """ |
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4 | /*************************************************************************** |
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5 | Name : RangeSlider |
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6 | Description : A slider for ranges |
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7 | Date : Jun 20, 2012 |
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8 | copyright : (C) 2012 by Giuseppe Sucameli |
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9 | email : brush.tyler@gmail.com |
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10 | |
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11 | the code is based on RangeSlider by phil |
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12 | (see https://svn.enthought.com/enthought/browser/TraitsBackendQt/trunk/enthought/traits/ui/qt4/extra/range_slider.py) licensed under GPLv2 |
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13 | ***************************************************************************/ |
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14 | |
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15 | /*************************************************************************** |
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16 | * * |
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17 | * This program is free software; you can redistribute it and/or modify * |
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18 | * it under the terms of the GNU General Public License as published by * |
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19 | * the Free Software Foundation; either version 2 of the License, or * |
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20 | * (at your option) any later version. * |
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21 | * * |
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22 | ***************************************************************************/ |
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23 | """ |
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24 | |
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25 | from PyQt4 import QtGui, QtCore |
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26 | |
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27 | class RangeSlider(QtGui.QSlider): |
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28 | """ A slider for ranges. |
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29 | |
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30 | This class provides a dual-slider for ranges, where there is a defined |
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31 | maximum and minimum, as is a normal slider, but instead of having a |
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32 | single slider value, there are 2 slider values. |
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33 | |
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34 | This class emits the same signals as the QSlider base class, with the |
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35 | exception of valueChanged. |
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36 | |
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37 | In addition, two new signals are emitted to catch the movement of |
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38 | each handle, lowValueChanged(int) and highValueChanged(int). |
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39 | """ |
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40 | highValueChanged = QtCore.pyqtSignal(int) |
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41 | lowValueChanged = QtCore.pyqtSignal(int) |
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42 | def __init__(self, *args): |
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43 | super(RangeSlider, self).__init__(*args) |
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44 | |
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45 | self._low = self.minimum() |
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46 | self._high = self.maximum() |
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47 | |
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48 | self.pressed_control = QtGui.QStyle.SC_None |
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49 | self.hover_control = QtGui.QStyle.SC_None |
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50 | self.click_offset = 0 |
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51 | |
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52 | # -1 for the low, 1 for the high, 0 for both |
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53 | self.active_slider = -1 |
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54 | |
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55 | def lowValue(self): |
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56 | return self._low |
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57 | |
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58 | def setLowValue(self, low): |
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59 | if low < self.minimum(): |
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60 | low = self.minimum() |
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61 | if low == self._low: |
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62 | return |
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63 | |
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64 | self._low = low |
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65 | self.update() |
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66 | |
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67 | if self.hasTracking(): |
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68 | self.lowValueChanged.emit(self._low) |
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69 | |
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70 | def highValue(self): |
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71 | return self._high |
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72 | |
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73 | def setHighValue(self, high): |
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74 | if high > self.maximum(): |
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75 | high = self.maximum() |
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76 | if high == self._high: |
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77 | return |
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78 | |
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79 | self._high = high |
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80 | self.update() |
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81 | |
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82 | if self.hasTracking(): |
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83 | self.lowValueChanged.emit(self._high) |
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84 | |
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85 | def paintEvent(self, event): |
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86 | # based on http://qt.gitorious.org/qt/qt/blobs/master/src/gui/widgets/qslider.cpp |
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87 | |
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88 | painter = QtGui.QPainter(self) |
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89 | style = QtGui.QApplication.style() |
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90 | |
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91 | for i, value in enumerate([self._low, self._high]): |
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92 | opt = QtGui.QStyleOptionSlider() |
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93 | self.initStyleOption(opt) |
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94 | |
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95 | gr = style.subControlRect(style.CC_Slider, opt, style.SC_SliderGroove, self) |
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96 | sr = style.subControlRect(style.CC_Slider, opt, style.SC_SliderHandle, self) |
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97 | |
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98 | if self.orientation() == QtCore.Qt.Horizontal: |
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99 | handle_length = sr.width() |
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100 | slider_length = gr.width() |
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101 | slider_min = gr.x() |
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102 | slider_max = gr.right() - handle_length + 1 |
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103 | else: |
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104 | handle_length = sr.height() |
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105 | slider_length = gr.height() |
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106 | slider_min = gr.y() |
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107 | slider_max = gr.bottom() - handle_length + 1 |
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108 | |
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109 | opt.subControls = QtGui.QStyle.SC_SliderGroove | QtGui.QStyle.SC_SliderHandle |
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110 | |
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111 | # draw the first slider with inverted appearance, then the second |
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112 | # slider drawn on top of the existing ones |
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113 | if i == 0: |
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114 | if self.orientation() == QtCore.Qt.Horizontal: |
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115 | opt.upsideDown = not self.invertedAppearance() |
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116 | else: |
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117 | opt.upsideDown = self.invertedAppearance() |
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118 | |
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119 | if self.orientation() == QtCore.Qt.Horizontal: |
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120 | opt.sliderValue = value - self.minimum() |
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121 | opt.sliderPosition = self.minimum() + (self.maximum() - value) |
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122 | |
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123 | opt.rect.setX(slider_min) |
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124 | opt.rect.setWidth(slider_length) |
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125 | |
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126 | else: |
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127 | opt.rect.setY(slider_min) |
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128 | opt.rect.setHeight(slider_length) |
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129 | |
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130 | else: |
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131 | # do not highlight the second part when has focus to avoid |
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132 | # drawing of partially overlapped semi-transparent backgrounds |
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133 | opt.state &= ~QtGui.QStyle.State_HasFocus |
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134 | |
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135 | opt.sliderValue = 0 |
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136 | opt.sliderPosition = self.minimum() |
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137 | |
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138 | if self.orientation() == QtCore.Qt.Horizontal: |
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139 | opt.upsideDown = self.invertedAppearance() |
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140 | |
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141 | pos = style.sliderPositionFromValue(0, self.maximum()-self.minimum(), |
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142 | value-self.minimum(), slider_max - slider_min - 4, |
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143 | opt.upsideDown) |
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144 | |
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145 | opt.rect.setX(pos + 3) |
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146 | opt.rect.setWidth(slider_max - pos + handle_length - 3) |
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147 | |
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148 | else: |
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149 | opt.upsideDown = not self.invertedAppearance() |
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150 | |
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151 | pos = style.sliderPositionFromValue(0, self.maximum()-self.minimum(), |
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152 | self.maximum()-value, slider_max - slider_min - 4, |
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153 | opt.upsideDown) |
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154 | |
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155 | opt.rect.setY(slider_min-1) |
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156 | opt.rect.setHeight(slider_min + slider_length - pos - 2) |
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157 | |
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158 | if self.tickPosition() != self.NoTicks: |
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159 | opt.subControls |= QtGui.QStyle.SC_SliderTickmarks |
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160 | |
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161 | if self.pressed_control: |
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162 | opt.activeSubControls = self.pressed_control |
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163 | opt.state |= QtGui.QStyle.State_Sunken |
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164 | else: |
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165 | opt.activeSubControls = self.hover_control |
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166 | |
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167 | style.drawComplexControl(QtGui.QStyle.CC_Slider, opt, painter, self) |
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168 | |
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169 | |
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170 | def mousePressEvent(self, event): |
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171 | event.accept() |
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172 | |
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173 | style = QtGui.QApplication.style() |
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174 | button = event.button() |
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175 | |
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176 | # In a normal slider control, when the user clicks on a point in the |
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177 | # slider's total range, but not on the slider part of the control the |
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178 | # control would jump the slider value to where the user clicked. |
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179 | # For this control, clicks which are not direct hits will slide both |
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180 | # slider parts |
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181 | |
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182 | if button: |
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183 | opt = QtGui.QStyleOptionSlider() |
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184 | self.initStyleOption(opt) |
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185 | |
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186 | self.active_slider = 0 |
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187 | mid = (self.maximum() - self.minimum()) / 2.0 |
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188 | |
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189 | for i, value in enumerate([self._low, self._high]): |
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190 | opt.sliderPosition = value |
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191 | hit = style.hitTestComplexControl(style.CC_Slider, opt, event.pos(), self) |
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192 | |
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193 | if hit == style.SC_SliderHandle: |
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194 | self.pressed_control = hit |
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195 | |
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196 | # if both handles are close together, avoid locks |
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197 | # choosing the one with more empty space near it |
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198 | if self._low + 2 >= self._high: |
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199 | self.active_slider = 1 if self._high < mid else -1 |
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200 | else: |
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201 | self.active_slider = -1 if i == 0 else 1 |
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202 | self.triggerAction(self.SliderMove) |
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203 | self.setRepeatAction(self.SliderNoAction) |
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204 | self.setSliderDown(True) |
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205 | break |
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206 | |
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207 | if self.active_slider == 0: |
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208 | self.pressed_control = QtGui.QStyle.SC_SliderHandle |
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209 | self.click_offset = self.__pixelPosToRangeValue(self.__pick(event.pos())) |
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210 | self.triggerAction(self.SliderMove) |
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211 | self.setRepeatAction(self.SliderNoAction) |
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212 | self.setSliderDown(True) |
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213 | else: |
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214 | event.ignore() |
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215 | |
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216 | def mouseReleaseEvent(self, event): |
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217 | if self.pressed_control != QtGui.QStyle.SC_SliderHandle: |
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218 | event.ignore() |
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219 | return |
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220 | |
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221 | self.setSliderDown(False) |
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222 | return QtGui.QSlider.mouseReleaseEvent(self, event) |
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223 | |
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224 | def mouseMoveEvent(self, event): |
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225 | if self.pressed_control != QtGui.QStyle.SC_SliderHandle: |
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226 | event.ignore() |
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227 | return |
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228 | |
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229 | event.accept() |
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230 | new_pos = self.__pixelPosToRangeValue(self.__pick(event.pos())) |
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231 | opt = QtGui.QStyleOptionSlider() |
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232 | self.initStyleOption(opt) |
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233 | |
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234 | old_click_offset = self.click_offset |
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235 | self.click_offset = new_pos |
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236 | |
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237 | if self.active_slider == 0: |
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238 | offset = new_pos - old_click_offset |
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239 | new_low = self._low + offset |
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240 | new_high = self._high + offset |
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241 | |
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242 | if new_low < self.minimum(): |
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243 | diff = self.minimum() - new_low |
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244 | new_low += diff |
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245 | new_high += diff |
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246 | if new_high > self.maximum(): |
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247 | diff = self.maximum() - new_high |
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248 | new_low += diff |
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249 | new_high += diff |
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250 | |
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251 | self.setLowValue( new_low ) |
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252 | self.setHighValue( new_high ) |
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253 | |
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254 | elif self.active_slider < 0: |
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255 | if new_pos > self._high: |
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256 | new_pos = self._high |
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257 | self.setLowValue( new_pos ) |
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258 | |
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259 | else: |
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260 | if new_pos < self._low: |
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261 | new_pos = self._low |
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262 | self.setHighValue( new_pos ) |
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263 | |
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264 | if self.hasTracking(): |
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265 | self.emit(QtCore.SIGNAL('sliderMoved(int)'), new_pos) |
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266 | |
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267 | |
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268 | def __pick(self, pt): |
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269 | if self.orientation() == QtCore.Qt.Horizontal: |
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270 | return pt.x() |
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271 | else: |
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272 | return pt.y() |
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273 | |
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274 | |
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275 | def __pixelPosToRangeValue(self, pos): |
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276 | opt = QtGui.QStyleOptionSlider() |
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277 | self.initStyleOption(opt) |
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278 | style = QtGui.QApplication.style() |
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279 | |
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280 | gr = style.subControlRect(style.CC_Slider, opt, style.SC_SliderGroove, self) |
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281 | sr = style.subControlRect(style.CC_Slider, opt, style.SC_SliderHandle, self) |
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282 | |
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283 | if self.orientation() == QtCore.Qt.Horizontal: |
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284 | handle_length = sr.width() |
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285 | slider_min = gr.x() + handle_length/2 |
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286 | slider_max = gr.right() - handle_length/2 + 1 |
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287 | else: |
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288 | handle_length = sr.height() |
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289 | slider_min = gr.y() + handle_length/2 |
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290 | slider_max = gr.bottom() - handle_length/2 + 1 |
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291 | |
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292 | return self.minimum() + style.sliderValueFromPosition(0, self.maximum()-self.minimum(), |
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293 | pos-slider_min, slider_max - slider_min, |
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294 | opt.upsideDown) |
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