cola/widgets/text.py

   1 from PyQt4 import QtGui
   2 from PyQt4 import QtCore
   3 from PyQt4.QtCore import SIGNAL
   4
   5
   6 class HintedTextWidgetEventFilter(QtCore.QObject):
   7     def __init__(self, parent):
   8         super(HintedTextWidgetEventFilter, self).__init__(parent)
   9         self.widget = parent
  10
  11     def eventFilter(self, obj, event):
  12         if event.type() == QtCore.QEvent.FocusIn:
  13             self.widget.emit_position()
  14             if self.widget.is_hint():
  15                 self.widget.enable_hint(False)
  16
  17         elif event.type() == QtCore.QEvent.FocusOut:
  18             if not bool(self.widget.value()):
  19                 self.widget.enable_hint(True)
  20
  21         return False
  22
  23
  24 class HintedTextWidgetMixin(object):
  25     def __init__(self, hint):
  26         self._hint = unicode(self.tr(hint))
  27         self._event_filter = HintedTextWidgetEventFilter(self)
  28         self.installEventFilter(self._event_filter)
  29
  30         # Palette for normal text
  31         self.default_palette = QtGui.QPalette(self.palette())
  32
  33         # Palette used for the placeholder text
  34         self.hint_palette = pal = QtGui.QPalette(self.palette())
  35         color = self.hint_palette.text().color()
  36         color.setAlpha(128)
  37         pal.setColor(QtGui.QPalette.Active, QtGui.QPalette.Text, color)
  38         pal.setColor(QtGui.QPalette.Inactive, QtGui.QPalette.Text, color)
  39
  40     def emit_position(self):
  41         pass
  42
  43     def reset_cursor(self):
  44         pass
  45
  46     def set_hint(self, hint):
  47         is_hint = self.is_hint()
  48         self._hint = hint
  49         if is_hint:
  50             self.enable_hint(True)
  51
  52     def hint(self):
  53         return self._hint
  54
  55     def is_hint(self):
  56         return self.strip() == self._hint
  57
  58     def value(self):
  59         text = self.strip()
  60         if text == self._hint:
  61             return u''
  62         else:
  63             return text
  64
  65     def strip(self):
  66         return self.as_unicode().strip()
  67
  68     def enable_hint(self, hint):
  69         blocksignals = self.blockSignals(True)
  70         if hint:
  71             self.set_value(self.hint())
  72         else:
  73             self.clear()
  74         self.reset_cursor()
  75         self.blockSignals(blocksignals)
  76         self.enable_hint_palette(hint)
  77
  78     def enable_hint_palette(self, hint):
  79         if hint:
  80             self.setPalette(self.hint_palette)
  81         else:
  82             self.setPalette(self.default_palette)
  83
  84     def refresh_palette(self):
  85         self.enable_hint_palette(self.is_hint())
  86
  87
  88 class HintedTextEdit(QtGui.QTextEdit, HintedTextWidgetMixin):
  89     def __init__(self, hint, parent=None):
  90         QtGui.QTextEdit.__init__(self, parent)
  91         HintedTextWidgetMixin.__init__(self, hint)
  92
  93         self.setLineWrapMode(QtGui.QTextEdit.NoWrap)
  94         self.setAcceptRichText(False)
  95
  96         self.connect(self, SIGNAL('cursorPositionChanged()'),
  97                      self.emit_position)
  98
  99     def as_unicode(self):
 100         return unicode(self.toPlainText())
 101
 102     def set_value(self, value):
 103         self.setPlainText(value)
 104         self.refresh_palette()
 105
 106     def emit_position(self):
 107         cursor = self.textCursor()
 108         position = cursor.position()
 109         txt = self.as_unicode()
 110         rows = txt[:position].count('\n') + 1
 111         cols = cursor.columnNumber()
 112         self.emit(SIGNAL('cursorPosition(int,int)'), rows, cols)
 113
 114
 115 class HintedLineEdit(QtGui.QLineEdit, HintedTextWidgetMixin):
 116     def __init__(self, hint, parent=None):
 117         QtGui.QLineEdit.__init__(self, parent)
 118         HintedTextWidgetMixin.__init__(self, hint)
 119
 120         self.connect(self,
 121                      SIGNAL('cursorPositionChanged(int,int)'),
 122                      lambda x, y: self.emit_position())
 123
 124     def emit_position(self):
 125         cols = self.cursorPosition()
 126         self.emit(SIGNAL('cursorPosition(int,int)'), 1, cols)
 127
 128     def set_value(self, value):
 129         self.setText(value)
 130         self.refresh_palette()
 131
 132     def as_unicode(self):
 133         return unicode(self.text())
 134
 135     def reset_cursor(self):
 136         self.setCursorPosition(0)