Like other things posted here without notices to the contrary, this
code is in the public domain.
This is a relatively responsive pager program for text files, much
like 'more' or 'less', but in a GUI, so it zooms in and out with the +
and - keys.
It's written in Python with PyQt.
#!/usr/bin/python
import qt, sys, time, qd
class mailviewer(qt.QWidget):
def __init__(self, filename, parent=None):
qt.QWidget.__init__(self, parent, None,
qt.Qt.WStaticContents | qt.Qt.WRepaintNoErase)
self.fontSize = 10
self.setFont()
self.setEraseColor(self.white)
self.setFocusPolicy(qt.QWidget.StrongFocus)
self.file = file(filename)
self.filePos = 0
self.prevPoses = []
self.startTime = time.time()
def setFont(self):
# to get this font name, I used this to select from the dialog box:
# self.font, ok = qt.QFontDialog.getFont(self.font)
# It's Palatino.
self.font = qt.QFont('Urw Palladio l', self.fontSize)
def adjustFontSize(self, delta):
self.fontSize += delta
self.setFont()
self.update()
def pageUp(self):
if self.prevPoses:
self.filePos = self.prevPoses.pop()
self.update()
def pageDown(self):
self.prevPoses.append(self.filePos)
self.filePos = self.newPos
self.update()
def keyPressEvent(self, ev):
self.startTime = time.time()
key = ev.key()
if key in [qt.Qt.Key_Plus, qt.Qt.Key_Equal]:
self.adjustFontSize(delta = +2)
elif key in [qt.Qt.Key_Minus]:
self.adjustFontSize(delta = -2)
elif key in [qt.Qt.Key_Next, qt.Qt.Key_Space]:
self.pageDown()
elif key in [qt.Qt.Key_Prior, qt.Qt.Key_Backspace]:
self.pageUp()
else:
self.startTime = None
ev.ignore()
return
ev.accept()
def lineReader(self):
self.file.seek(self.filePos)
return iter(self.file)
def paintEvent(self, ev):
if self.startTime is None: self.startTime = time.time()
pix = qt.QPixmap(self.size())
pix.fill(self, 0, 0)
pa = qt.QPainter(pix)
pa.setFont(self.font)
linespacing = pa.fontMetrics().lineSpacing()
y = linespacing
lines = self.lineReader()
height = self.height()
try:
self.newPos = self.filePos
while y < height + linespacing:
rawline = lines.next()
self.newPos += len(rawline)
pa.drawText(10, y, qd.chomp(qd.untabify(rawline)))
y += linespacing
except StopIteration:
pass # ran out of lines!
pa.end()
npa = qt.QPainter(self)
npa.drawPixmap(0, 0, pix)
npa.setFont(qt.QFont('Helvetica', 10))
npa.setPen(self.darkGray)
npa.drawText(self.width() - 40, npa.fontMetrics().lineSpacing(),
str(time.time() - self.startTime))
if __name__ == '__main__':
a = qt.QApplication(sys.argv)
w = mailviewer(sys.argv[1])
a.setMainWidget (w)
w.show()
w.setFocus()
a.exec_loop()
Here's qd.py, which it depends on:
def chomp(text):
while text[-1:] in ['\r', '\n']: text = text[:-1]
return text
assert chomp('a\n') == 'a'
assert chomp('\n') == ''
assert chomp('') == ''
def untabify(text):
def dumb_tab_exp(char):
if char != '\t': return char
return ' '
return ''.join(map(dumb_tab_exp, text))
