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/*
* java-gnome, a UI library for writing GTK and GNOME programs from Java!
*
* Copyright © 2007-2010 Operational Dynamics Consulting, Pty Ltd and Others
*
* The code in this file, and the program it is a part of, is made available
* to you by its authors as open source software: you can redistribute it
* and/or modify it under the terms of the GNU General Public License version
* 2 ("GPL") as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GPL for more details.
*
* You should have received a copy of the GPL along with this program. If not,
* see http://www.gnu.org/licenses/. The authors of this program may be
* contacted through http://java-gnome.sourceforge.net/.
*/
package treeview;
import org.gnome.gdk.Event;
import org.gnome.gtk.CellRendererText;
import org.gnome.gtk.DataColumn;
import org.gnome.gtk.DataColumnBoolean;
import org.gnome.gtk.DataColumnInteger;
import org.gnome.gtk.DataColumnString;
import org.gnome.gtk.Gtk;
import org.gnome.gtk.ListStore;
import org.gnome.gtk.TreeIter;
import org.gnome.gtk.TreePath;
import org.gnome.gtk.TreeView;
import org.gnome.gtk.TreeViewColumn;
import org.gnome.gtk.Widget;
import org.gnome.gtk.Window;
/**
* A tutorial example of using a TreeView backed by a ListStore. In this
* little demonstration, we list a number of famous hiking trails and how to
* get to them.
*
* @author Andrew Cowie
*/
public class ExampleTrailHeads
{
public ExampleTrailHeads() {
final Window window;
final TreeView view;
final ListStore model;
TreeIter row;
CellRendererText renderer;
TreeViewColumn vertical;
window = new Window();
// ------------------------------------------------
final DataColumnString placeName;
final DataColumnString trailHead;
final DataColumnString elevationFormatted;
final DataColumnInteger elevationSort;
final DataColumnBoolean accessibleByTrain;
/*
* So we begin our explorations of the TreeView API here. First thing
* is to create a model. You'll notice we declared the variables
* above. You don't have to do that, of course, but it makes calling
* the ListStore constructor more palatable. More generally, you will
* frequently have the DataColumns as instance field variables (so
* they can be accessed throughout the file), rather than just local
* variables. So you'll end up pre-declaring them regardless, and that
* makes the constructor call nice and compact:
*/
model = new ListStore(new DataColumn[] {
placeName = new DataColumnString(),
trailHead = new DataColumnString(),
elevationFormatted = new DataColumnString(),
elevationSort = new DataColumnInteger(),
accessibleByTrain = new DataColumnBoolean()
});
/*
* You almost never populate your TreeModels with data statically from
* your source code. We have done so here to demonstrate the use of
* appendRow() to get a new horizontal data row and then the various
* forms of setValue() to store data in that row.
*
* In practise, however, you will find the setting of data to be
* fairly involved; after all, it takes some trouble to decide what
* you want to display, extract if from your domain object layer and
* format it prior to insertion into the TreeModel for display by a
* TreeView.
*
* Notice the use of Pango markup in the placeName column. This can be
* a powerful way of improving your information density, but be aware
* that if some rows have multiple lines and some don't, the row
* height will be inconsistent and will look really ugly. So make sure
* they all have the same font information and number of newlines. You
* would use utility methods to help keep things organized, of course,
* but we've kept it straight forward here.
*/
row = model.appendRow();
model.setValue(row, placeName, "Blue Mountains national park\n<small>(Six Foot Track)</small>");
model.setValue(row, trailHead, "Katoomba, NSW, Australia");
model.setValue(row, elevationFormatted, "1015 m");
model.setValue(row, elevationSort, 1005);
model.setValue(row, accessibleByTrain, true);
row = model.appendRow();
model.setValue(row, placeName, "Kilimanjaro\n<small>(Machame route)</small>");
model.setValue(row, trailHead, "Nairobi, Kenya");
model.setValue(row, elevationFormatted, "5894 m");
model.setValue(row, elevationSort, 5894);
model.setValue(row, accessibleByTrain, false);
row = model.appendRow();
model.setValue(row, placeName, "Appalachian Trail\n<small>(roller coaster section)</small>");
model.setValue(row, trailHead, "Harpers Ferry, West Virginia, USA");
model.setValue(row, elevationFormatted, "147 m");
model.setValue(row, elevationSort, 147);
model.setValue(row, accessibleByTrain, true);
/*
* Now onto the view side. First we need the top level TreeView which
* is the master Widget into which everything else is mixed.
*/
view = new TreeView(model);
/*
* Now the vertical display columns. The sequence is to get a
* TreeViewColumn, then create the CellRenderer to be put into it, and
* then set whatever data mappings are appropriate along with any
* settings for the vertical TreeViewColumn. This is the heart of the
* TreeView/TreeModel API
*
* Note that we reuse the renderer and vertical variables; unlike the
* DataColumns, there's no need to keep coming up with unique column
* names as you rarely need to reference them later.
*/
vertical = view.appendColumn();
vertical.setTitle("Place");
renderer = new CellRendererText(vertical);
renderer.setMarkup(placeName);
vertical = view.appendColumn();
vertical.setTitle("Nearest town");
renderer = new CellRendererText(vertical);
renderer.setText(trailHead);
renderer.setAlignment(0.0f, 0.0f);
vertical.setExpand(true);
vertical = view.appendColumn();
vertical.setTitle("Elevation");
renderer = new CellRendererText(vertical);
renderer.setText(elevationFormatted);
renderer.setAlignment(0.0f, 0.0f);
/*
* Because the elevation is a formatted String, it won't sort
* properly. So we use a DataColumnInteger populated with the raw
* altitude number to indicate the sort order. (If you don't believe
* me, try changing the sort column to elevationFormatted instead of
* elevationSort, and you'll see it order as 1015, 147, 5894). As
* you'll see from the documentation, setSortColumn() also makes the
* headers clickable, which saves you having to mess with TreeView's
* setHeadersClickable() or TreeViewColumn's setClickable(), although
* there are occasional use cases for them.
*
* Then we call emitClicked() to force the header we want things to be
* sorted on to actually be active. This is especially necessary if
* you've defined sorting for more than one vertical column, but if
* you want sorting on from the start, you need to call it.
*/
vertical.setSortColumn(elevationSort);
vertical.emitClicked();
/*
* And that's it! You've now done everything you need to have a
* working TreeView.
*
* ... except that if it's for more than information, you probably
* want something to happen when someone clicks on a row. So, we hook
* up a handler to the TreeView.RowActivated signal. The TreePath it
* gives you is the useful bit.
*/
view.connect(new TreeView.RowActivated() {
public void onRowActivated(TreeView source, TreePath path, TreeViewColumn vertical) {
final TreeIter row;
final String place, height;
row = model.getIter(path);
place = model.getValue(row, trailHead);
height = model.getValue(row, elevationFormatted);
System.out.println("You want to go to " + place + " in order to climb to " + height);
}
});
/*
* The rest of this file is the usual minimum wrapper to make this
* presentable as a Window on the display.
*/
// ------------------------------------------------
window.add(view);
window.setTitle("Trail Heads");
window.showAll();
window.connect(new Window.DeleteEvent() {
public boolean onDeleteEvent(Widget source, Event event) {
Gtk.mainQuit();
return false;
}
});
}
public static void main(String[] args) {
Gtk.init(args);
new ExampleTrailHeads();
Gtk.main();
}
}
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