161. How to insert links in GtkTextView - Part 5 - Display Tooltip over Link?

Problem

You want to allow users to insert links in a GtkTextView. The user will highlight some text and press the "Insert Link" button. A popup dialog box will appear where the user enters the URL address. On pressing return, the URL address will be registered, and the link highlighted in the standard blue underlined text.

  • In Part 1, we have the link displayed as blue underlined text.
  • In Part 2, we launch the link in the default browser when the user clicks on the link.
  • In Part 3, we display the url address in the status bar when the user hovers the mouse over the link.
  • In Part 4, we change the cursor when the user hovers the mouse over the link in the textview.

In this article, we will display a tooltip when the user hovers the mouse over the link in the textview as shown below:

How to insert links in GtkTextView - Part 5 - Display Tooltip over Link?


Solution


Sample Code

1   
 2   
 3   
 4   
 5   
 6   
 7   
 8   
 9   
 10   
 11   
 12   
 13   
 14   
 15   
 17   
 20   
 24   
 25   
 26   
 27   
 28   
 29   
 30   
 31   
 32   
 33   
 34   
 43   
 44   
 45   
 46   
 49   
 50   
 51   
 52   
 53   
 54   
 55   
 56   
 58   
 59   
 60   
 61   
 62   
 63   
 64   
 65   
 67   
 68   
 69   
 70   
 71   
 72   
 73   
 74   
 75   
 76   
 83   
 84   
 85   
 86   
 87   
 88   
 89   
 90   
 92   
 93   
 94   
 95   
 96   
 98   
100   
101   
102   
106   
107   
108   
110   
111   
112   
114   
115   
116   
117   
118   
119   
120   
122   
123   
125   
134   
135   
136   
137   
138   
139   
140   
141   
144   
145   
146   
147   
148   
149   
150   
151   
153   
154   
156   
159   
160   
161   
162   
164   
165   
168   
169   
170   
171   
172   
173   
174   
175   
180   
181   
182   
183   
184   
185   
186   
187   
191   
192   
193   
194   
195   
196   
197   
198   
199   
200   
201   
203   
204   
206   
207   
208   
209   
210   
211   
212   
213   
214   
216   
220   
221   
222   
223   
225   
226   
227   
228   
229   
231   
232   
233   
234   
235   
236   
237   
239   
240   
241   
242   
243   
244   
245   
246   
247   
248   
249   
250   
251   
252   
253   
257   
258   
259   
260   
261   
262   
263   
264   
265   
266   
268   
269   
270   
271   
272   
273   
274   
275   
280   
281   
282   
283   
284   
285   
286   
287   
288   
289   
290   
291   
292   
293   
294   
295   
296   
297   
298   
299   
<?php
$window = new GtkWindow();
$window->set_size_request(400, 240);
$window->connect_simple('destroy', array('Gtk','main_quit'));
$window->add($vbox = new GtkVBox());

// display title
$title = new GtkLabel("Insert Links in GtkTextView - Part 5\n".
"Display Tooltip over Link");
$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);
$title->set_justify(Gtk::JUSTIFY_CENTER);
$alignment = new GtkAlignment(0.5, 0.5, 0, 0);
$alignment->add($title);
$vbox->pack_start($alignment);

// Setup TextBuffer and TextView
$tag_count = 0;
$buffer = new GtkTextBuffer();
$buffer->set_text('PHP-GTK2 resources:
1) manual: http://gtk.php.net/manual/en/gtkclasses.php
2) mailing list: http://www.nabble.com/Php---GTK---General-f171.html
');
$view = new GtkTextView();
$view->set_buffer($buffer);
$view->modify_font(new PangoFontDescription("Arial 10"));
$view->set_wrap_mode(Gtk::WRAP_WORD);
$buffer->connect('mark-set', 'on_mark_set');
$view->connect('motion-notify-event', 'on_motion_in_textview');
$view->set_events(Gdk::POINTER_MOTION_MASK);


$hbox = new GtkHBox();
$hbox->pack_start($button = new GtkButton('Insert Link'), 0);
$vbox->pack_start($hbox, 0);
$button->connect('clicked', 'on_button', $buffer);

$scrolled_win = new GtkScrolledWindow();
$scrolled_win->set_policy( Gtk::POLICY_AUTOMATIC, Gtk::POLICY_AUTOMATIC);

$scrolled_win->add($view);
$vbox->pack_start($scrolled_win);

// setup status area
$status = new GtkStatusbar(); // note 1
$vbox->pack_start($status, 0);

$window->show_all();

$standard_cursor = new GdkCursor(Gdk::XTERM);
$link_cursor = new GdkCursor(Gdk::DRAFT_LARGE);

$tooltips = new TreeviewTooltips(); // note 1

Gtk::main();

// Setup highlight tag

class LinkTag extends GtkTextTag {
    function __construct($link) {
        global $buffer;
        parent::__construct();
        $tag_table = $buffer->get_tag_table();
        $this->set_property('foreground', "#0000ff");
        $this->set_property('underline', Pango::UNDERLINE_SINGLE);
        $tag_table->add($this);
    }
}

function on_button($button, $buffer) {
    global $view, $tag, $url, $tag_count;

    $cursor_pos = $buffer->get_mark('insert');
    $iter = $buffer->get_iter_at_mark($cursor_pos);

    list($start, $end) = $buffer->get_selection_bounds();
    if ($start==null || $end==null) return; // no selection

    $url[$tag_count] = prompt("Enter URL:");
    $tag[$tag_count] = new LinkTag($url[$tag_count]);
    $buffer->apply_tag($tag[$tag_count], $start, $end);
    ++$tag_count;

    $buffer->place_cursor($end);
    $view->grab_focus();
}

function on_mark_set($buffer, $textiter, $textmark) {

    global $tag, $url, $tag_count;

    if ($textmark->get_name()!='insert') return;

    $cursor_pos = $buffer->get_insert();
    $iter = $buffer->get_iter_at_mark($cursor_pos);

    for ($i=0; $i<$tag_count; ++$i) {
        if ($iter->has_tag($tag[$i])) {
            if (PHP_SHLIB_SUFFIX=='dll') {
                $shell = new COM('WScript.Shell');
                $shell->Run('cmd /c start "" "' . $url[$i] . '"', 0, FALSE);
                unset($shell);
            } else {
                exec("firefox $url[$i] > /dev/null &");
            }
        } else {
        }
    }
    return true;
}

function on_motion_in_textview($view, $event) {
    global $standard_cursor, $link_cursor;
    $buffer_location = $view->window_to_buffer_coords
        (Gtk::TEXT_WINDOW_TEXT, $event->x, $event->y);
    $iter = $view->get_iter_at_location(
        $buffer_location[0], $buffer_location[1]);
    if ($iter==null) return;

    global $tag, $url, $tag_count, $status;
    for ($i=0; $i<$tag_count; ++$i) {
        $context_id = $status->get_context_id('msg1');
        if ($iter->has_tag($tag[$i])) {
            $status->pop($context_id);
            $status->push($context_id, $url[$i]);
            $view->get_window(Gtk::TEXT_WINDOW_TEXT)->set_cursor($link_cursor);

            global $tooltips;
            $tooltips->on_motion($event, $url[$i]); // note 2
            break;
        } else {
            $status->pop($context_id);
            $view->get_window(Gtk::TEXT_WINDOW_TEXT)->set_cursor($standard_cursor);

            global $tooltips;
            $tooltips->on_leave($event); // note 3
        }
    }
}

//function to prompt for user data
function prompt($str) {
    $prompt = new Prompt($str);
    $input = $prompt->entry->get_text();
    return $input;
}

class Prompt{

    var $entry; // the user input

    function Prompt($str) {
        $dialog = new GtkDialog('Prompt', null, Gtk::DIALOG_MODAL);
        $top_area = $dialog->vbox;
        $top_area->pack_start($hbox = new GtkHBox());
        $stock = GtkImage::new_from_stock(Gtk::STOCK_DIALOG_QUESTION,
            Gtk::ICON_SIZE_DIALOG);
        $hbox->pack_start($stock, 0, 0);
        $hbox->pack_start(new GtkLabel($str));
        $this->entry = new GtkEntry();
        $hbox->pack_start($this->entry, 0, 0);
        $hbox->pack_start(new GtkLabel(' '), 0, 0);

        $dialog->add_button(Gtk::STOCK_OK, Gtk::RESPONSE_OK);

        $buttons = $dialog->action_area->get_children();
        $button_ok = $buttons[0]; // get the ID of the OK button
        // simulate button click when user press enter
        $this->entry->connect('activate', array(&$this, 'on_enter'), $button_ok);

        $dialog->set_has_separator(false);
        $dialog->show_all();
        $dialog->run();
        $dialog->destroy();
    }

    // simulate button click when user press enter
    function on_enter($entry, $button) {
        $button->clicked();
    }

}

// the class to display tooltips in treeview
class TreeviewTooltips {

    function TreeviewTooltips() {
        // create the tooltip window
        $this->tooltip_window = new GtkWindow(Gtk::WINDOW_POPUP);
        $this->tooltip_window->set_name('gtk-tooltips');
        $this->tooltip_window->set_resizable(False);
        $this->tooltip_window->set_border_width(4);
        $this->tooltip_window->set_app_paintable(True);
        $this->tooltip_window->connect('expose-event', array(&$this, 'on_expose_event'));

        $label = new GtkLabel('');
        $label->set_line_wrap(True);
        $label->set_alignment(0.5, 0.5);
        $label->set_use_markup(True);
        $label->show();
        $this->tooltip_window->add($label);
    }

    function on_motion($event, $msg) {

        $size = $this->tooltip_window->size_request();
        $this->tooltip_window->move($event->x_root - $size->width/2, $event->y_root + 12);
        $this->tooltip_window->child->set_text($msg);
        $this->tooltip_window->show();
    }

    function on_leave($event) {
        $this->tooltip_window->hide();
    }

    function on_expose_event($tooltip_window, $event) {
        $size = $tooltip_window->size_request();
        $tooltip_window->style->paint_flat_box($tooltip_window->window, Gtk::STATE_NORMAL,
        Gtk::SHADOW_OUT, null, $tooltip_window, 'tooltip', 0, 0, $size->width, $size->height);
    }
}

?>

Output

As shown above.
 

Explanation

We make use of the code in Part 4.

We also make use of the code in How to display tooltips in GtkTreeView - Part 1? to display the tooltips.

What's new here:

  1. Set up the tooltips.
  2. Display the tooltip.
  3. Hide the tooltip.

Note

This example works only on windows. It does not work on Linux. This is because for some reason, GtkTextView does not emit the signal motion-notify-event in linux. So there's no way you can know if the current mouse location is over a link.

Related Links

Add comment

Security code
Refresh