PHP-GTK2 Newsletter

PHP-GTK2 Tips & Techniques
FREE Newsletter
by kksou



Sample Code 348: How to scroll to newly inserted item in a linear list using GtkTreeView - Part 2 - setting GtkAdjustment of GtkScrolledWindow?
Written by kksou   
Tuesday, 23 October 2007
Problem

This is in response to vlada's post titled "Automatic scrolling".

He has inserted some items in a linear list using GtkTreeView, and he would like to the treeview to automatically scroll to the newly inserted item.

In Part 1, we make use of the mathod GtkTreeView::scroll_to_cell().

In this Part 2, we achieve the same effect by setting GtkAdjustment of GtkScrolledWindow as shown below:

How to scroll to newly inserted item in a linear list using GtkTreeView - Part 2 - setting GtkAdjustment of GtkScrolledWindow?


Solution

Sample Code
1   
2   
3   
4   
5   
6   
7   
8   
9   
10   
11   
12   
13   
14   
15   
16   
17   
18   
19   
20   
21   
22   
23   
24   
25   
26   
27   
28   
29   
30   
31   
32   
33   
34   
35   
36   
37   
38   
39   
40   
41   
42   
43   
44   
45   
46   
47   
48   
49   
50   
51   
52   
53   
54   
55   
56   
57   
58   
59   
60   
61   
62   
63   
64   
65   
66   
67   
68   
69   
70   
71   
72   
73   
74   
75   
76   
77   
78   
79   
80   
81   
82   
83   
84   
85   
86   
87   
88   
<?php
$window = new GtkWindow();
$window->set_size_request(400, 210);
$window->connect_simple('destroy', array('Gtk','main_quit'));
$window->add($vbox = new GtkVBox());

// display title
$title = new GtkLabel("          Scroll to newly inserted item in linear list\n".
"Part 2 - setting GtkAdjustment of GtkScrolledWindow");
$title->modify_font(new PangoFontDescription("Times New Roman Italic 10"));
$title->modify_fg(Gtk::STATE_NORMAL, GdkColor::parse("#0000ff"));
$title->set_size_request(-1, 40);
$vbox->pack_start($title, 0, 0);

$vbox->pack_start($hbox = new GtkHBox(), 0, 0);
$button = new GtkButton('Insert New Item');
$hbox->pack_start($button, 0, 0);
$button->connect('clicked', 'on_click');

// the 2D table
$data = array(
array('row0', 'item 42', 2, 3.1),
array('row1', 'item 36', 20, 6.21),
array('row2', 'item 21', 8, 9.36),
array('row3', 'item 10', 11, 12.4),
array('row4', 'item 7', 5, 15.5),
array('row5', 'item 4', 17, 18.6),
array('row6', 'item 3', 20, 21.73));

display_table($vbox, $data);

$window->show_all();
Gtk::main();

function display_table($vbox, $data) {

    // Set up a scroll window
    global $scrolled_win;
    $scrolled_win = new GtkScrolledWindow();
    $scrolled_win->set_policy( Gtk::POLICY_AUTOMATIC,
        Gtk::POLICY_AUTOMATIC);
    $vbox->pack_start($scrolled_win);

    // Creates the list store
    global $view, $model;
    if (defined("GObject::TYPE_STRING")) {
        $model = new GtkListStore(GObject::TYPE_STRING, GObject::TYPE_STRING,
            GObject::TYPE_LONG, GObject::TYPE_DOUBLE);
    } else {
        $model = new GtkListStore(Gtk::TYPE_STRING, Gtk::TYPE_STRING,
            Gtk::TYPE_LONG, Gtk::TYPE_DOUBLE);
    }
    $field_header = array('Row #', 'Description', 'Qty', 'Price');
    $field_justification = array(0.0, 0.0, 0.5, 1.0);

    // Creates the view to display the list store
    $view = new GtkTreeView($model);
    $scrolled_win->add($view);

    // Creates the columns
    for ($col=0; $col<count($field_header); ++$col) {
        $cell_renderer = new GtkCellRendererText();
        $cell_renderer->set_property("xalign", $field_justification[$col]);
        $column = new GtkTreeViewColumn($field_header[$col],
            $cell_renderer, 'text', $col);
        $column->set_alignment($field_justification[$col]);
        $column->set_sort_column_id($col);

        // set the header font and color
        $label = new GtkLabel($field_header[$col]);
        $label->modify_font(new PangoFontDescription("Arial Bold"));
        $label->modify_fg(Gtk::STATE_NORMAL, GdkColor::parse("#0000FF"));
        $column->set_widget($label);
        $label->show();

        // setup self-defined function to display alternate row color
        $column->set_cell_data_func($cell_renderer, "format_col", $col);
        $view->append_column($column);
    }

    // pupulates the data
    for ($row=0; $row<count($data); ++$row) {
        $values = array();
        for ($col=0; $col<count($data[$row]); ++$col) {
            $values[] = $data[$row][$col];
        }
        $model->append($values);
    }
  • Note that this is only 70% of the sample code. You have to be a registered member to see the entire sample code. Please login or register.
  • Registration is free and immediate.
  • Have some doubt about the registration? Please read this forum article.
Explanation

The above code is based on How to scroll to newly inserted item in a linear list using GtkTreeView - Part 1 - using GtkTreeView scroll_to_cell?

What's new here:

  1. Get the vadjustment.
  2. Scroll to the last row by setting the vadjustment to the upper boundary (i.e. the maximum value)

Related Links

User reviews   Average user ratings:    4.0   (from 1 user)
  1. Tom Bell from Australia
    September 23, 2008 8:05pm

Note: You have to be a registered member to leave a comment. Free registration here.

 
< Prev   Next >

Blog - Forum - Privacy Policy - Contact Us
Copyright © 2006-2008. kksou.com. All Rights Reserved