Commit ca9d15df authored by Carlos Garnacho's avatar Carlos Garnacho

scrolledwindow: Add ::edge-overshot signal

This signal is emitted whenever user scrolling hits the overshoot
edge in the given direction. May be useful to add "reload" or "load
more" behaviors in apps.

https://bugzilla.gnome.org/show_bug.cgi?id=738534
parent c84f544f
......@@ -208,6 +208,7 @@ enum
{
SCROLL_CHILD,
MOVE_FOCUS_OUT,
EDGE_OVERSHOT,
LAST_SIGNAL
};
......@@ -545,7 +546,33 @@ gtk_scrolled_window_class_init (GtkScrolledWindowClass *class)
_gtk_marshal_VOID__ENUM,
G_TYPE_NONE, 1,
GTK_TYPE_DIRECTION_TYPE);
/**
* GtkScrolledWindow::edge-overshot:
* @scrolled_window: a #GtkScrolledWindow
* @pos: edge side that was hit
*
* The ::edge-overshot signal is emitted whenever user initiated scrolling
* makes the scrolledwindow firmly surpass (ie. with some edge resistance)
* the lower or upper limits defined by the adjustment in that orientation.
*
* If a similar behavior without edge resistance is desired, one alternative
* may be to check on #GtkAdjustment::value-changed that the value equals
* either #GtkAdjustment:lower or #GtkAdjustment:upper - #GtkAdjustment:page-size.
*
* Note: The @pos argument is LTR/RTL aware, so callers should be aware too
* if intending to provide behavior on horizontal edges.
*
* Since: 3.16
*/
signals[EDGE_OVERSHOT] =
g_signal_new (I_("edge-overshot"),
G_TYPE_FROM_CLASS (gobject_class),
G_SIGNAL_RUN_LAST, 0,
NULL, NULL,
g_cclosure_marshal_generic,
G_TYPE_NONE, 1, GTK_TYPE_POSITION_TYPE);
binding_set = gtk_binding_set_by_class (class);
add_scroll_binding (binding_set, GDK_KEY_Left, GDK_CONTROL_MASK, GTK_SCROLL_STEP_BACKWARD, TRUE);
......@@ -2525,20 +2552,46 @@ _gtk_scrolled_window_set_adjustment_value (GtkScrolledWindow *scrolled_window,
{
GtkScrolledWindowPrivate *priv = scrolled_window->priv;
gdouble lower, upper, *prev_value;
GtkPositionType edge_pos;
gboolean vertical;
lower = gtk_adjustment_get_lower (adjustment) - MAX_OVERSHOOT_DISTANCE;
upper = gtk_adjustment_get_upper (adjustment) -
gtk_adjustment_get_page_size (adjustment) + MAX_OVERSHOOT_DISTANCE;
if (adjustment == gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar)))
prev_value = &priv->unclamped_hadj_value;
vertical = FALSE;
else if (adjustment == gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar)))
vertical = TRUE;
else
return;
if (vertical)
prev_value = &priv->unclamped_vadj_value;
else
prev_value = &priv->unclamped_hadj_value;
value = CLAMP (value, lower, upper);
if (*prev_value == value)
return;
*prev_value = CLAMP (value, lower, upper);
*prev_value = value;
gtk_adjustment_set_value (adjustment, value);
if (value == lower)
edge_pos = vertical ? GTK_POS_TOP : GTK_POS_LEFT;
else if (value == upper)
edge_pos = vertical ? GTK_POS_BOTTOM : GTK_POS_RIGHT;
else
return;
/* Invert horizontal edge position on RTL */
if (!vertical &&
gtk_widget_get_direction (GTK_WIDGET (scrolled_window)) == GTK_TEXT_DIR_RTL)
edge_pos = (edge_pos == GTK_POS_LEFT) ? GTK_POS_RIGHT : GTK_POS_LEFT;
g_signal_emit (scrolled_window, signals[EDGE_OVERSHOT], 0, edge_pos);
}
static gboolean
......
......@@ -133,6 +133,7 @@ noinst_PROGRAMS = $(TEST_PROGS) \
testexpander \
testvolumebutton \
testscrolledwindow \
testscrolledge \
testswitch \
testcellarea \
testswitch \
......@@ -270,6 +271,7 @@ testgrouping_DEPENDENCIES = $(TEST_DEPS)
testtooltips_DEPENDENCIES = $(TEST_DEPS)
testvolumebutton_DEPENDENCIES = $(TEST_DEPS)
testscrolledwindow_DEPENDENCIES = $(TEST_DEPS)
testscrolledge_DEPENDENCIES = $(TEST_DEPS)
testcellarea_DEPENDENCIES = $(TEST_DEPS)
testtreemenu_DEPENDENCIES = $(TEST_DEPS)
testwindows_DEPENDENCIES = $(TEST_DEPS)
......
/* testscrolledge.c
*
* Copyright (C) 2014 Matthias Clasen <mclasen@redhat.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <gtk/gtk.h>
static guint add_rows_id = 0;
static void
populate_list (GtkListBox *list)
{
gint i;
gchar *text;
GtkWidget *row, *label;
gint n;
GList *l;
l = gtk_container_get_children (GTK_CONTAINER (list));
n = g_list_length (l);
g_list_free (l);
for (i = 1; i <= 50; i++)
{
row = gtk_list_box_row_new ();
text = g_strdup_printf ("List row %d", i + n);
label = gtk_label_new (text);
g_free (text);
g_object_set (label, "margin", 10, NULL);
gtk_widget_set_halign (label, GTK_ALIGN_START);
gtk_container_add (GTK_CONTAINER (row), label);
gtk_widget_show_all (row);
gtk_container_add (GTK_CONTAINER (list), row);
}
}
static GtkWidget *popup;
static GtkWidget *spinner;
static gboolean
add_rows (gpointer data)
{
GtkListBox *list = data;
gtk_widget_hide (popup);
gtk_spinner_stop (GTK_SPINNER (spinner));
populate_list (list);
add_rows_id = 0;
return G_SOURCE_REMOVE;
}
static void
edge_overshot (GtkScrolledWindow *sw,
GtkPositionType pos,
GtkListBox *list)
{
if (pos == GTK_POS_BOTTOM)
{
gtk_spinner_start (GTK_SPINNER (spinner));
gtk_widget_show (popup);
if (add_rows_id == 0)
add_rows_id = g_timeout_add (2000, add_rows, list);
}
}
int
main (int argc, char *argv[])
{
GtkWidget *win;
GtkWidget *sw;
GtkWidget *list;
GtkWidget *overlay;
GtkWidget *label;
gtk_init (NULL, NULL);
win = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_default_size (GTK_WINDOW (win), 600, 400);
overlay = gtk_overlay_new ();
popup = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
gtk_widget_set_halign (popup, GTK_ALIGN_CENTER);
gtk_widget_set_valign (popup, GTK_ALIGN_END);
g_object_set (popup, "margin", 40, NULL);
label = gtk_label_new ("Getting more rows...");
spinner = gtk_spinner_new ();
gtk_widget_show (spinner);
gtk_widget_show (label);
gtk_container_add (GTK_CONTAINER (popup), label);
gtk_container_add (GTK_CONTAINER (popup), spinner);
gtk_overlay_add_overlay (GTK_OVERLAY (overlay), popup);
gtk_widget_set_no_show_all (popup, TRUE);
sw = gtk_scrolled_window_new (NULL, NULL);
gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw), GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);
list = gtk_list_box_new ();
gtk_list_box_set_selection_mode (GTK_LIST_BOX (list), GTK_SELECTION_NONE);
gtk_container_add (GTK_CONTAINER (win), overlay);
gtk_container_add (GTK_CONTAINER (overlay), sw);
gtk_container_add (GTK_CONTAINER (sw), list);
populate_list (GTK_LIST_BOX (list));
g_signal_connect (sw, "edge-overshot", G_CALLBACK (edge_overshot), list);
gtk_widget_show_all (win);
gtk_main ();
return 0;
}
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