John's Blog

#!/usr/bin/env python
 
from PyQt4.Qt import *
from PyQt4.QtGui import *
 
class ComboModel(QAbstractListModel):
 
    MAX_ITEMS = 5
    items = [u'123', u'456', u'789']
 
    # Required to get a working model.
    def rowCount(self, parent=QModelIndex()):
        # This is a List model meaning all elements are root elements.
        if parent and parent.isValid():
            return 0
        return len(self.items)
 
    # Required to get a working model.
    def insertRows(self, row, count, parent=QModelIndex()):
        self.beginInsertRows(parent, 0, 1)
        self.endInsertRows()
        return True
 
    def data(self, index, role):
        if role in (Qt.DisplayRole, Qt.EditRole):
            return QVariant(self.items[index.row()])
        return QVariant()
 
    def setData(self, index, value, role):
        value = unicode(value.toString())
        if value in self.items:
            # Move the item to the top of the list.
            del self.items[self.items.index(value)]
            self.items.insert(0, value)
        else:
            # Add the new item to the top of the list.
            self.items.insert(0, value)
            self.remove_items()
        self.emit(SIGNAL('dataChanged(QModelIndex, QModelIndex)'),
            self.createIndex(0, 0), self.createIndex(len(self.items) - 1, 0))
        return True
 
    def remove_items(self):
        '''
        Checks the number of items in the list and if it has been exceeded
        removes extra items.
        '''
        if len(self.items) > self.MAX_ITEMS:
            count = len(self.items) - self.MAX_ITEMS
            del self.items[-count:]
 
    def order_items(self, index):
        '''
        Move the selected item tot he top of the list.
        '''
        # We only need to move the item to the top if it is not the first item.
        if index > 0:
            self.emit(SIGNAL('layoutAboutToBeChanged()'))
            value = self.items[index]
            del self.items[index]
            self.items.insert(0, value)
            self.emit(SIGNAL('layoutChanged()'))
 
 
class MComboBox(QComboBox):
 
    def __init__(self, parent=None):
        QComboBox.__init__(self, parent)
        self.setEditable(True)
        # The default policy is InsertAtBottom. InsertAtTop must be set
        # otherwise the model will move the item to the top and the QComboBox
        # will select the last index. In the case of reaching max items the
        # index will be invalid because the removal is after the QComboBox has
        # stored the value of the last index.
        self.setInsertPolicy(QComboBox.InsertAtTop)
        # Without this the QComboBox will not call set data for us to check
        # for items already in the model if the item is a duplicate.
        self.setDuplicatesEnabled(True)
        self._model = ComboModel()
        self.setModel(self._model)
 
        # We need to tell the model when an item is selected so it can be moved
        # to the top of the history list.
        self.connect(self, SIGNAL('activated(int)'), self._model.order_items)
 
 
def main():
    app = QApplication([])
 
    bx = MComboBox()
    bx.show()
 
    app.exec_()
 
if __name__ == '__main__':
    main()

#!/usr/bin/env python
 
'''
Copyright (c) 2009 John Schember 
 
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
'''
 
import sys
 
from PyQt4.Qt import Qt, QObject, QApplication, QLineEdit, QCompleter, \
    QStringListModel, SIGNAL
 
TAGS = ['Nature', 'buildings', 'home', 'City', 'country', 'Berlin']
 
class CompleterLineEdit(QLineEdit):
 
    def __init__(self, *args):
        QLineEdit.__init__(self, *args)
 
        QObject.connect(self, SIGNAL('textChanged(QString)'), self.text_changed)
 
    def text_changed(self, text):
        all_text = unicode(text)
        text = all_text[:self.cursorPosition()]
        prefix = text.split(',')[-1].strip()
 
        text_tags = []
        for t in all_text.split(','):
            t1 = unicode(t).strip()
            if t1 != '':
                text_tags.append(t)
        text_tags = list(set(text_tags))
 
        self.emit(SIGNAL('text_changed(PyQt_PyObject, PyQt_PyObject)'),
            text_tags, prefix)
 
    def complete_text(self, text):
        cursor_pos = self.cursorPosition()
        before_text = unicode(self.text())[:cursor_pos]
        after_text = unicode(self.text())[cursor_pos:]
        prefix_len = len(before_text.split(',')[-1].strip())
        self.setText('%s%s, %s' % (before_text[:cursor_pos - prefix_len], text,
            after_text))
        self.setCursorPosition(cursor_pos - prefix_len + len(text) + 2)
 
 
class TagsCompleter(QCompleter):
 
    def __init__(self, parent, all_tags):
        QCompleter.__init__(self, all_tags, parent)
        self.all_tags = set(all_tags)
 
    def update(self, text_tags, completion_prefix):
        tags = list(self.all_tags.difference(text_tags))
        model = QStringListModel(tags, self)
        self.setModel(model)
 
        self.setCompletionPrefix(completion_prefix)
        if completion_prefix.strip() != '':
            self.complete()
 
 
def main():
    app = QApplication(sys.argv)
 
    editor = CompleterLineEdit()
 
    completer = TagsCompleter(editor, TAGS)
    completer.setCaseSensitivity(Qt.CaseInsensitive)
 
    QObject.connect(editor,
        SIGNAL('text_changed(PyQt_PyObject, PyQt_PyObject)'),
        completer.update)
    QObject.connect(completer, SIGNAL('activated(QString)'),
        editor.complete_text)
 
    completer.setWidget(editor)
 
    editor.show()
 
    return app.exec_()
 
if __name__ == '__main__':
    main()

/*
Copyright (c) 2008 John Schember 
 
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
 
/*
Ensures that there are 3 newline characters at the end of the file (two blank
lines after the last of the text). This assumes Unix \n line characters. Please
use dos2unix before running to ensure that the end of line characters are
correct.
*/
 
#include <QFile>
#include <QString>
#include <QTextStream>
 
int main(int argc, char **argv)
{
    // Stream to write errors to the console.
    QTextStream errStream(stderr);
 
    // Store for the contents of the ebook.
    QString content;
 
    // We need an ebook file to work on.
    if (argc != 2) {
        errStream << QObject::tr("Error: No input file") << endl;
        return 1;
    }
 
    QFile ebook(argv[1]);
    if (!ebook.open(QIODevice::ReadWrite | QIODevice::Text)) {
        errStream << QObject::tr("Error: Could not open") << endl;
        return 1;
    }
 
    // We use a QTextStream to actually work on the file.
    QTextStream ioStream(&ebook);
 
    // We want to see what the last 3 characters are at the end of the file.
    ioStream.seek(ebook.size() - 3);
    content = ioStream.read(3);
 
    // Move to the end of the file because we want to add newlines (\n&#39;s) to
    // the end.
    ioStream.seek(ebook.size());
 
    // We want 3 newline (\n) characters at the end of the file. Add them until
    // they total 3.
    for (int i = 0; i < (3 - content.count("\n")); i++) {
        ioStream << "\n" << flush;
    }
 
    ebook.close();
 
    return 0;
}

/*
Copyright (c) 2008 John Schember 
 
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
 
/*
Reflows txt file ebook paragraphs. Paragraphs should be separated by a blank
line. Takes paragraphs that have hard breaks and puts all lines onto a single
line.
 
For Example:
 
INPUT
 
This is a multi line paragraph. It comprises
a few lines but has hard
breaks.
 
Now for the second
borken apart paragraph.
 
OUTPUT
 
This is a multi line paragraph. It comprises a few lines but has hard breaks.
 
Now for the second broken apart paragraph.
*/
 
#include <QFile>
#include <QRegExp>
#include <QString>
#include <QTextStream>
 
int main(int argc, char** argv)
{
    // Stream to write errors to the console.
    QTextStream errStream(stderr);
 
    // Regular expression to search for broken paragraphs. Works by looking
    // for char newline char. A proper ebook should have paragraphs separated
    // by a blank line meaning char newline newline char.
    QRegExp re("[^\n]\n[^\n]");
 
    // Store for the contents of the ebook.
    QString content;
 
    // We need an ebook file to work on.
    if (argc != 2) {
        errStream << QObject::tr("Error: No input file") << endl;
        return 1;
    }
 
    QFile ebook(argv[1]);
    if (!ebook.open(QIODevice::ReadWrite | QIODevice::Text)) {
        errStream << QObject::tr("Error: Could not open") << endl;
        return 1;
    }
 
    // We use a QTextStream to actually work on the file.
    QTextStream ioStream(&ebook);
    // Read the entire file contents into memory.
    content = ioStream.readAll();
 
    while (content.contains(re)) {
        // Remove the newline when there is a match with the regular expression.
        content = content.replace(content.indexOf(re)+1, 1, " ");
    }
 
    // Truncate the ebook so we don&#39;t end up with the original contents after
    // our modified contents.
    if (!ebook.resize(0)) {
        errStream << QObject::tr("Error: Could not truncate file") << endl;
        return 1;
    }
 
    // Store the modified content back on disk.
    ioStream.seek(0);
    ioStream << content;
 
    ebook.close();
 
    return 0;
}

/*
Copyright (c) 2008 John Schember 
 
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
 
/*
Removes extraneous whitespace in a txt file ebook. This will remove every
'\t', '\v', '\f', '\r', and will replace multiple occurrences ' ' with a single
one.
 
For Example:
 
INPUT
 
      This     is a bad                          line.
 
Now for  the     second     borken line.
 
OUTPUT
 
This is a bad line.
 
Now for the second borken line.
 
*/
 
#include 
#include 
#include 
 
int main(int argc, char **argv)
{
    // Stream to write errors to the console.
    QTextStream errStream(stderr);
 
    // Store for the contents of the ebook.
    QString content;
 
    // We need an ebook file to work on.
    if (argc != 2) {
        errStream << QObject::tr("Error: No input file") << endl;
        return 1;
    }
 
    QFile ebook(argv[1]);
    if (!ebook.open(QIODevice::ReadWrite | QIODevice::Text)) {
        errStream << QObject::tr("Error: Could not open") << endl;
        return 1;
    }
 
    // We use a QTextStream to actually work on the file.
    QTextStream ioStream(&ebook);
 
    // Read every line and remove the extras we don&#39;t want.
    while (!ioStream.atEnd()) {
        content += ioStream.readLine().simplified() + "\n";
    }
 
    // Truncate the ebook so we don&#39;t end up with the original contents after
    // our modified contents.
    if (!ebook.resize(0)) {
        errStream << QObject::tr("Error: Could not truncate file") << endl;
        return 1;
    }
 
    // Store the modified content back on disk.
    ioStream.seek(0);
    ioStream << content;
 
    ebook.close();
 
    return 0;
}