452. How to drag and drop between two thumbnail images using GtkIconView - Part 2 - left to right insert?

Problem

Suppose you have displayed two lists of thumbnail images using GtkIconView, and you would like to allow users to drag and drop images between the two views.

In Part 1, the dropped image is appended to the end of the dropped view.

In this Part 2, I'll show you how to insert image at the dropped location.

How to drag and drop between two thumbnail images using GtkIconView - Part 2 - left to right insert?


Solution

Use the technique as outlined in the article How to drag and drop between 2 GtkTreeViews - Part 3 - left to right with insert? to insert the dragged image at the dropped location.

Important Note: This only works for PHP-GTK2 compliled with gtk+ v2.10 and above. If you are using an older version, for linux, you may follow the step-by-step instructions to recompile php-gtk2 with gtk+ v2.10. For windows, please refer to How to install php gtk2 on windows? You may also want to take a look here to see some of the new exciting PHP-GTK2 Functionalities.


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.

 square_red.jpg
 square_yellow.jpg
 square_green.jpg
 square_blue.jpg
 square_blue2.jpg
 square_blue3.jpg
 ball_red.png
 ball_yellow.png
 ball_blue3.png
 ball_blue3a.png
 ball_green3.png
 ball_green4.png

1   
2   
3   
4   
7   
8   
9   
10   
11   
12   
13   
14   
15   
16   
17   
18   
19   
22   
23   
26   
27   
28   
29   
30   
31   
34   
35   
36   
37   
38   
39   
40   
41   
42   
43   
44   
45   
46   
47   
48   
49   
50   
51   
52   
56   
59   
60   
61   
62   
63   
65   
66   
67   
69   
70   
71   
72   
74   
75   
76   
77   
78   
79   
80   
81   
82   
83   
84   
85   
86   
87   
88   
89   
90   
92   
94   
95   
96   
97   
98   
99   
100   
110   
111   
112   
113   
116   
117   
118   
119   
121   
123   
124   
125   
128   
129   
130   
131   
132   
133   
135   
136   
137   
138   
139   
140   
141   
143   
144   
145   
146   
148   
150   
151   
153   
154   
156   
157   
158   
160   
161   
162   
<?php
$window = new GtkWindow();
$window->set_title($argv[0]);
$window->set_size_request(600, 400);
$window->connect_simple('destroy', array('Gtk','main_quit'));
$window->add($vbox = new GtkVBox());

// display title
$title = new GtkLabel("Drag and drop between two thumbnail images using GtkIconView\n".
"                            Part 2 - Left to right (insert)");
$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); // add a small gap

// Set up the two views
$hpane = new GtkHPaned();
$vbox->pack_start($hpane);

// the thumbnail image lists
// 0 = left
// 1 = right
$imagelist[0] = array('square_red.jpg', 'square_yellow.jpg', 'square_green.jpg',
    'square_blue.jpg', 'square_blue2.jpg', 'square_blue3.jpg');
$imagelist[1] = array('ball_red.png', 'ball_yellow.png',
    'ball_blue3.png', 'ball_blue3a.png',
    'ball_green3.png', 'ball_green4.png',);

$left_vbox = setup_iconview(0, 'left');
$right_vbox = setup_iconview(1, 'right');

// setup drag and drop
$view[0]->drag_source_set(Gdk::BUTTON1_MASK, array( array( 'text/plain', 0, 0)),
    Gdk::ACTION_COPY|Gdk::ACTION_MOVE);
$view[0]->connect('drag-data-get', 'on_drag');

$view[1]->drag_dest_set(Gtk::DEST_DEFAULT_ALL,
array( array( 'text/plain', 0, 0)), Gdk::ACTION_COPY|Gdk::ACTION_MOVE);
$view[1]->connect('drag-data-received', 'on_drop');

$hpane->add1($left_vbox);
$hpane->add2($right_vbox);
$view[0]->set_size_request(300, -1);

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

function setup_iconview($id, $label) {
    global $imagelist, $model, $modelfilter, $view;
    $model[$id] = new GtkListStore(GdkPixbuf::gtype, Gtk::TYPE_STRING);
    foreach($imagelist[$id] as $img) {
        $pixbuf = GdkPixbuf::new_from_file($img);
        $model[$id]->append(array($pixbuf, $img));
    }

    $view[$id] = new GtkIconView($model[$id]);
    $view[$id]->set_pixbuf_column(0); // col 0 of the model
    $view[$id]->set_text_column(1); // col 1 of the model
    $view[$id]->set_selection_mode(Gtk::SELECTION_MULTIPLE);
    $view[$id]->set_columns(0);
    $view[$id]->set_item_width(120);

    $vbox = new GtkVBox();
    $scrolled_win = new GtkScrolledWindow();
    $scrolled_win->set_policy( Gtk::POLICY_AUTOMATIC,
        Gtk::POLICY_AUTOMATIC);
    $vbox->pack_start($scrolled_win);
    $scrolled_win->add($view[$id]);
    return $vbox;
}

// process drag
function on_drag($widget, $context, $data, $info, $time) {
    $selection = $widget->get_selected_items();
    if (count($selection)==0) return;  // return if there's no selection
    $data->set_text(serialize($selection));
}

// process drop
function on_drop($widget, $context, $x, $y, $data, $info, $time) {
    // append the dragged item to the destination view

    $drop_info = $widget->get_dest_item_at_pos($x, $y); // note 1
    if ($drop_info) {
        list($path, $position) = $drop_info; // note 2
        $func = 'insert';
        if ($position == Gtk::TREE_VIEW_DROP_BEFORE || // note 3
        $position == Gtk::TREE_VIEW_DROP_INTO_OR_BEFORE) { 
            $pos = $path[0]; // note 4
        } else {
            $pos = $path[0]+1; // note 5
        }
    } else {
        $func = 'append';
    }

    global $imagelist;
    global $model, $modelfilter, $view;
    $data = unserialize($data->data);
    $dest_model = $widget->get_model();
    $source_model = $view[0]->get_model();
    foreach($data as $img) {
        $i = $img[0];

        // remove the source image first
        $iter = $model[0]->get_iter($i);
        $img_name = $model[0]->get_value($iter, 1);
        $model[0]->remove($iter);

        // append the dragged image to the destination
        $pixbuf = GdkPixbuf::new_from_file($img_name);

        if ($func=='append') {
            $dest_model->append(array($pixbuf, $img_name)); // note 6
        } elseif ($func = 'insert') {
            $dest_model->insert($pos, array($pixbuf, $img_name)); // note 7
        }
    }
}

?>

Output

As shown above.

 

Explanation

The above sample code is based on Part 1.

We also make use of the code from How to drag and drop between 2 GtkTreeViews - Part 3 - left to right with insert? to insert the dragged image at the dropped location.

What's new here:

  1. Get the drop information.
  2. Get the path and position of the drop information.
  3. Check whether it's on, before or after the row.
  4. If it's on or before, we insert into the current row.
  5. If it's after, we insert into the next row (i.e. current_row + 1).
  6. Append the dragged image.
  7. Insert the dragged image at the dropped location.

Related Links

Add comment


Security code
Refresh