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Problem At least for now, there is still no GtkCellRenderer yet to display a native button inside a treeview.
However, since the main functionality of a button is to respond to button clicks, we can simulate a button using gif, png or jpg image files as shown below.
To make the button more realistic, I used two gif images for the button one more button up, and one for button down.
Solution
- We make use of the signal button-press-event on the treeview to detect any "clicks" on the image button.
- We make use of the signal button-release-event on the treeview to detect when the user releases the button.
- We make use of the technique from How to display gif or jpg images in GtkTreeView - Part 1? to display a gif image in treeview.
- Note that I've made extensive use of the notation
$model[$path][$col_num]. This greatly simplifies the codes instead of using $model->get_value($iter, $col_num) and $model->set($iter, $col_num, $value) (in which case you have to always convert the path to the iter first). If you're not familiar with this, I would strongly encourage you to read this article by Andrei Zmievski titled New GtkTreeModel functionality.
Sample Code The following image files are required by the sample code below. Please save a copy of the image files and put them in the same directory where you store the sample code.
 | button_click.gif |
 | button_click2.gif |
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| <?php
$window = new GtkWindow();
$window->set_size_request(400, 200);
$window->connect_simple('destroy', array('Gtk','main_quit'));
$window->add($vbox = new GtkVBox());
// display title
$title = new GtkLabel("Setup a button in GtkTreeView - Part 1");
$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(new GtkLabel(), 0, 0);
// the 2D table
$data = array(
array('row0', 'item 42', 2, 3.1, 0),
array('row1', 'item 36', 20, 6.21, 0),
array('row2', 'item 21', 8, 9.36, 0),
array('row3', 'item 10', 11, 12.4, 0),
array('row4', 'item 7', 5, 15.5, 0),
array('row5', 'item 4', 17, 18.6, 0),
array('row6', 'item 3', 20, 21.73, 0));
display_table($vbox, $data);
$window->show_all();
Gtk::main();
function display_table($vbox, $data) {
// Set up a scroll window
$scrolled_win = new GtkScrolledWindow();
$scrolled_win->set_policy( Gtk::POLICY_AUTOMATIC,
Gtk::POLICY_AUTOMATIC);
$vbox->pack_start($scrolled_win);
// Creates the list store
if (defined("GObject::TYPE_STRING")) {
$model = new GtkListStore(GObject::TYPE_STRING, GObject::TYPE_STRING,
GObject::TYPE_LONG, GObject::TYPE_DOUBLE, GObject::TYPE_LONG);
} else {
$model = new GtkListStore(Gtk::TYPE_STRING, Gtk::TYPE_STRING,
Gtk::TYPE_LONG, Gtk::TYPE_DOUBLE, Gtk::TYPE_LONG);
}
$field_header = array('Row #', 'Description', 'Qty', 'Price', 'Action');
$field_justification = array(0.0, 0.0, 0.5, 1.0, 0.0);
// Creates the view to display the list store
$view = new GtkTreeView($model);
$scrolled_win->add($view);
$view->connect('button-press-event', 'on_buttonpress', $model); // note 1
$view->connect('button-release-event', 'on_buttonrelease', $model); // note 2
// Creates the columns
for ($col=0; $col<count($field_header); ++$col) {
if ($col==4) {
$cell_renderer = new GtkCellRendererPixbuf(); // note 3
$column = new GtkTreeViewColumn();
$column->pack_start($cell_renderer);
$column->set_title($field_header[$col]);
} else {
$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);
if ($col==1) $column->set_expand(1);
}
// 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);
}
$selection = $view->get_selection();
$selection->set_mode(Gtk::SELECTION_NONE);
}
// self-defined function to display alternate row color
function format_col($column, $cell, $model, $iter, $col_num) {
if ($col_num==4) {
if ($model[$iter][4]) { // note 4
$pixbuf = GdkPixbuf::new_from_file("button_click2.gif"); // note 4
} else {
$pixbuf = GdkPixbuf::new_from_file("button_click.gif"); // note 4
}
$cell->set_property('pixbuf', $pixbuf);
}
$path = $model->get_path($iter);
$row_num = $path[0];
$row_color = ($row_num%2==1) ? '#dddddd' : '#ffffff';
$cell->set_property('cell-background', $row_color);
}
|
- 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
- Detect button click on the treeview.
- Detect button release on the treeview.
- Set up the column where the button image will appear. Note that there is no image loaded at this point in time. The respective images are loaded in the custom cell display function.
- This is the part that sets the image button depending on the status of the button.
- Try clicking the button in very fast sequence, and take note of the output in the command window. You will see that even though the treeview might not reflect that clicks fast enough, all the button clicks are indeed being captured.
- This function takes care of the case when the user clicks on a button, holds on to the mouse button, and moves away from the button. Since there is no button-release signal, the button will still be in the 'clicked' state. This function serves to release any previous button clicks that have not been released.
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