Tuesday, April 16, 2013

Advanced widgets in PyGTK

Advanced widgets in PyGTK

In this part of the PyGTK programming tutorial, we will introduce some more advanced widgets in PyGTK.

IconView

The IconView is a widget which displays a list of icons in a grid.
iconview.py
#!/usr/bin/python

# ZetCode PyGTK tutorial
#
# This example demonstrates the IconView widget.
# It shows the contents of the currently selected
# directory on the disk.
#
# author: jan bodnar
# website: zetcode.com
# last edited: February 2009

import gtk
import os

COL_PATH = 0
COL_PIXBUF = 1
COL_IS_DIRECTORY = 2


class PyApp(gtk.Window):
def __init__(self):
super(PyApp, self).__init__()

self.set_size_request(650, 400)
self.set_position(gtk.WIN_POS_CENTER)

self.connect("destroy", gtk.main_quit)
self.set_title("IconView")

self.current_directory = '/'

vbox = gtk.VBox(False, 0);

toolbar = gtk.Toolbar()
vbox.pack_start(toolbar, False, False, 0)

self.upButton = gtk.ToolButton(gtk.STOCK_GO_UP);
self.upButton.set_is_important(True)
self.upButton.set_sensitive(False)
toolbar.insert(self.upButton, -1)

homeButton = gtk.ToolButton(gtk.STOCK_HOME)
homeButton.set_is_important(True)
toolbar.insert(homeButton, -1)

self.fileIcon = self.get_icon(gtk.STOCK_FILE)
self.dirIcon = self.get_icon(gtk.STOCK_DIRECTORY)

sw = gtk.ScrolledWindow()
sw.set_shadow_type(gtk.SHADOW_ETCHED_IN)
sw.set_policy(gtk.POLICY_AUTOMATIC, gtk.POLICY_AUTOMATIC)
vbox.pack_start(sw, True, True, 0)

self.store = self.create_store()
self.fill_store()

iconView = gtk.IconView(self.store)
iconView.set_selection_mode(gtk.SELECTION_MULTIPLE)

self.upButton.connect("clicked", self.on_up_clicked)
homeButton.connect("clicked", self.on_home_clicked)

iconView.set_text_column(COL_PATH)
iconView.set_pixbuf_column(COL_PIXBUF)

iconView.connect("item-activated", self.on_item_activated)
sw.add(iconView)
iconView.grab_focus()

self.add(vbox)
self.show_all()

def get_icon(self, name):
theme = gtk.icon_theme_get_default()
return theme.load_icon(name, 48, 0)


def create_store(self):
store = gtk.ListStore(str, gtk.gdk.Pixbuf, bool)
store.set_sort_column_id(COL_PATH, gtk.SORT_ASCENDING)
return store


def fill_store(self):
self.store.clear()

if self.current_directory == None:
return

for fl in os.listdir(self.current_directory):

if not fl[0] == '.':
if os.path.isdir(os.path.join(self.current_directory, fl)):
self.store.append([fl, self.dirIcon, True])
else:
self.store.append([fl, self.fileIcon, False])



def on_home_clicked(self, widget):
self.current_directory = os.path.realpath(os.path.expanduser('~'))
self.fill_store()
self.upButton.set_sensitive(True)


def on_item_activated(self, widget, item):

model = widget.get_model()
path = model[item][COL_PATH]
isDir = model[item][COL_IS_DIRECTORY]

if not isDir:
return

self.current_directory = self.current_directory + os.path.sep + path
self.fill_store()
self.upButton.set_sensitive(True)


def on_up_clicked(self, widget):
self.current_directory = os.path.dirname(self.current_directory)
self.fill_store()
sensitive = True
if self.current_directory == "/": sensitive = False
self.upButton.set_sensitive(sensitive)


PyApp()
gtk.main()
This example shows icons of the currently selected directory. It has a toolbar and two buttons. Up button and home button. We use them to navigate through the file system.
 self.current_directory = '/'
The current_directory is the directory, that is displayed by the IconView widget.
 def create_store(self):
store = gtk.ListStore(str, gtk.gdk.Pixbuf, bool)
store.set_sort_column_id(COL_PATH, gtk.SORT_ASCENDING)
return store
The create_store() method creates a ListStore. It is a data model used in IconViewwidget. It takes three parameters. The directory name, the pixbuf image of the icon and a bool variable, indicating, whether we have a directory or a file.
 if not fl[0] == '.': 
if os.path.isdir(os.path.join(self.current_directory, fl)):
self.store.append([fl, self.dirIcon, True])
else:
self.store.append([fl, self.fileIcon, False])
In the fill_store() method, we fill the list store with data. Here, we find out all directories in the current path. We exclude the invisible directories, which begin with '.'.
 def on_home_clicked(self, widget):
self.current_directory = os.path.realpath(os.path.expanduser('~'))
self.fill_store()
self.upButton.set_sensitive(True)
If we click on the home button, the home directory becomes a current directory. We refill the list store. And make the up button active.
In the on_item_activated() method, we react to an event, which is generated, when we click on a icon from the icon view widget.
 model = widget.get_model()
path = model[item][COL_PATH]
isDir = model[item][COL_IS_DIRECTORY]

if not isDir:
return
We get the path of the activated item. And we determine, if it is a directory or a file. If it is a file, we return.
 self.current_directory = self.current_directory + os.path.sep + path
self.fill_store()
self.upButton.set_sensitive(True)
In case it is a directory, we replace the root with the current path, refill the store and make the up button sensitive.
 def on_up_clicked(self, widget):
self.current_directory = os.path.dirname(self.current_directory)
self.fill_store()
sensitive = True
if self.current_directory == "/": sensitive = False
self.upButton.set_sensitive(sensitive)
If we click on the up button, we replace the current directory with it's parent directory. Refill the list store. And the up button is activated, if we are below the root (/) directory of the file system.

IconView
Figure: IconView

ListView

In the following example, we use the TreeView widget to show a list view. Again the ListStore is used to store data.
listview.py
#!/usr/bin/python

# ZetCode PyGTK tutorial
#
# This example shows a TreeView widget
# in a list view mode
#
# author: jan bodnar
# website: zetcode.com
# last edited: February 2009


import gtk

actresses = [('jessica alba', 'pomona', '1981'), ('sigourney weaver', 'new york', '1949'),
('angelina jolie', 'los angeles', '1975'), ('natalie portman', 'jerusalem', '1981'),
('rachel weiss', 'london', '1971'), ('scarlett johansson', 'new york', '1984' )]


class PyApp(gtk.Window):
def __init__(self):
super(PyApp, self).__init__()

self.set_size_request(350, 250)
self.set_position(gtk.WIN_POS_CENTER)

self.connect("destroy", gtk.main_quit)
self.set_title("ListView")

vbox = gtk.VBox(False, 8)

sw = gtk.ScrolledWindow()
sw.set_shadow_type(gtk.SHADOW_ETCHED_IN)
sw.set_policy(gtk.POLICY_AUTOMATIC, gtk.POLICY_AUTOMATIC)

vbox.pack_start(sw, True, True, 0)

store = self.create_model()

treeView = gtk.TreeView(store)
treeView.connect("row-activated", self.on_activated)
treeView.set_rules_hint(True)
sw.add(treeView)

self.create_columns(treeView)
self.statusbar = gtk.Statusbar()

vbox.pack_start(self.statusbar, False, False, 0)

self.add(vbox)
self.show_all()


def create_model(self):
store = gtk.ListStore(str, str, str)

for act in actresses:
store.append([act[0], act[1], act[2]])

return store


def create_columns(self, treeView):

rendererText = gtk.CellRendererText()
column = gtk.TreeViewColumn("Name", rendererText, text=0)
column.set_sort_column_id(0)
treeView.append_column(column)

rendererText = gtk.CellRendererText()
column = gtk.TreeViewColumn("Place", rendererText, text=1)
column.set_sort_column_id(1)
treeView.append_column(column)

rendererText = gtk.CellRendererText()
column = gtk.TreeViewColumn("Year", rendererText, text=2)
column.set_sort_column_id(2)
treeView.append_column(column)


def on_activated(self, widget, row, col):

model = widget.get_model()
text = model[row][0] + ", " + model[row][1] + ", " + model[row][2]
self.statusbar.push(0, text)



PyApp()
gtk.main()
In our example, we show a list of six actresses in the TreeViewwidget. Each of the rows shows the name, the place of born and the year of born for each of them.
 def create_model(self):
store = gtk.ListStore(str, str, str)

for act in actresses:
store.append([act[0], act[1], act[2]])

return store
In the create_model() method, we create the list store. The list store has three parameters. The name of the actress, the place of born and year of born. This is the data model of our TreeViewwidget.
 treeView = gtk.TreeView(store)
treeView.connect("row-activated", self.on_activated)
treeView.set_rules_hint(True)
Here we create the TreeView widget, taking the list store as a parameter. set_rules_hint()method changes the background color of the every second row in the TreeView widget.
 rendererText = gtk.CellRendererText()

column = gtk.TreeViewColumn("Name", rendererText, text=0)
column.set_sort_column_id(0)
treeView.append_column(column)
In the create_columns() method, we add three columns to our TreeView widget. The above code creates a column displaying names of the actresses. The CellRendererTextretrieves its text from the first column of the tree model. (text=0)
 def on_activated(self, widget, row, col):

model = widget.get_model()
text = model[row][0] + ", " + model[row][1] + ", " + model[row][2]
self.statusbar.push(0, text)
If we double click on an item, we display the whole row in the statusbar.

ListView
Figure: ListView

Tree

In the last example of this chapter, we use the TreeViewwidget to show a hierarchical tree of data.
tree.py
#!/usr/bin/python

# ZetCode PyGTK tutorial
#
# This example shows a TreeView widget
# in a tree view mode
#
# author: jan bodnar
# website: zetcode.com
# last edited: February 2009

import gtk


class PyApp(gtk.Window):
def __init__(self):
super(PyApp, self).__init__()

self.set_size_request(400, 300)
self.set_position(gtk.WIN_POS_CENTER)

self.connect("destroy", gtk.main_quit)
self.set_title("Tree")

tree = gtk.TreeView()

languages = gtk.TreeViewColumn()
languages.set_title("Programming languages")

cell = gtk.CellRendererText()
languages.pack_start(cell, True)
languages.add_attribute(cell, "text", 0)

treestore = gtk.TreeStore(str)

it = treestore.append(None, ["Scripting languages"])
treestore.append(it, ["Python"])
treestore.append(it, ["PHP"])
treestore.append(it, ["Perl"])
treestore.append(it, ["Ruby"])

it = treestore.append(None, ["Compiling languages"])
treestore.append(it, ["C#"])
treestore.append(it, ["C++"])
treestore.append(it, ["C"])
treestore.append(it, ["Java"])

tree.append_column(languages)
tree.set_model(treestore)

self.add(tree)
self.show_all()


PyApp()
gtk.main()
This time we use the TreeView widget to show hierarchical data.
 tree = gtk.TreeView()
TreeView widget is created.
 languages = gtk.TreeViewColumn()
languages.set_title("Programming languages")
It has one column named "Programming languages".
 cell = gtk.CellRendererText()
languages.pack_start(cell, True)
languages.add_attribute(cell, "text", 0)
We show textual data in the TreeView widget.
 treestore = gtk.TreeStore(str)
To store the data, we use the TreeStore object.
 it = treestore.append(None, ["Scripting languages"])
treestore.append(it, ["Python"])
treestore.append(it, ["PHP"])
We append data to the tree. The TreeIter object is used for accessing data in a row.
 tree.append_column(languages)
A column is appended to the tree.
 tree.set_model(treestore)
Finally, we set a data model for the tree widget.

Tree
Figure: Tree

In this chapter of the PyGTK programming tutorial, we were talking about advanced PyGTK widgets.

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