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Problem This is in response to cbell's post titled "Start processing automatically".
He has a program that does a bunch of stuff with a database and displays a progress bar as it proceeds. Currently the program is set up to begin processing when a button on the main window is clicked.
However he would like the program to begin processing as soon as it is started as shown below:
Solution
- You do not need to change any part of your code.
- All you need is to manually generate a click on the process button with GtkButton::clicked().
- Do this after you call
$window->show_all() and before calling Gtk::main().
- In this example, you will find that you can just generate the button click with
$button->clicked().
- However, you may find that this doesn't necessarily work for all applications.
- Here is a useful "trick" that you can learn from this example: generate the button click using
Gtk::idle_add(array($button, 'clicked')). In plain English, this means: let the control pass to the next statement (which is Gtk::main()) immediately, and generate a 'click' signal when you are free.
Sample Code 1
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| <?php
$window = new GtkWindow();
$window->set_size_request(400, 175);
$window->connect_simple('destroy', array('Gtk','main_quit'));
$window->add($vbox = new GtkVBox());
// display title
$title = new GtkLabel("Display progress bar ".
"while processing long task - Part 3\n".
" Begin processing automatically when program starts");
$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);
$vbox->pack_start(new GtkLabel('using Gtk::idle_add()'), 0, 0);
$vbox->pack_start(new GtkLabel('you can also interrupt the long task'), 0, 0);
$vbox->pack_start(new GtkLabel(), 0, 0);
$vbox->pack_start($hbox = new GtkHBox(), 0, 0);
$hbox->pack_start($button = new GtkButton('Start processing'), 1, 0);
$vbox->pack_start(new GtkLabel());
$button->connect('clicked', 'start_processing');
$window->show_all();
Gtk::idle_add(array($button, 'clicked')); // note 1
Gtk::main();
function start_processing($button) {
$do_long_task = new DoLongTask();
$do_long_task->idle_ID = Gtk::idle_add(
array(&$do_long_task, 'process_task'));
}
class DoLongTask {
var $progress_bar;
var $dialog;
var $subtask_count = 0;
var $max_task_count = 10;
var $idle_ID;
function DoLongTask() {
// setup a dialog containing progress bar
$dialog = new GtkDialog('Work in progress...',
null, Gtk::DIALOG_MODAL);
$top_area = $dialog->vbox;
$top_area->pack_start(new GtkLabel(
'Please hold on while processing data...'));
$this->progress_bar = new GtkProgressBar();
$this->progress_bar->set_orientation(Gtk::PROGRESS_LEFT_TO_RIGHT);
$top_area->pack_start($this->progress_bar, 0, 0);
$dialog->set_has_separator(false);
$dialog->show_all();
$this->dialog = $dialog;
$dialog->connect('delete-event',
array( &$this, "on_delete_event"));
}
// this is where you process your task
function process_task() {
echo "processing subtask $this->subtask_count: ";
for ($i=0; $i<10; ++$i) {
usleep(50000); // sleep for half a second
print ".";
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- 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 entire code is exactly the same as that of How to display progress bar while processing long task - Part 2 using_idle_add?
The only difference is the addition of the following line:
- Manually generate the 'clicked' signal on the process button.
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