PIKApp/app/display/pikadisplayshell-scrollbars.c

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2023-09-26 00:35:21 +02:00
/* PIKA - Photo and Image Kooker Application
* a rebranding of The GNU Image Manipulation Program (created with heckimp)
* A derived work which may be trivial. However, any changes may be (C)2023 by Aldercone Studio
*
* Original copyright, applying to most contents (license remains unchanged):
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* 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 <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <math.h>
#include <gegl.h>
#include <gtk/gtk.h>
#include "display-types.h"
#include "core/pikaimage.h"
#include "pikadisplay.h"
#include "pikadisplayshell.h"
#include "pikadisplayshell-scale.h"
#include "pikadisplayshell-scrollbars.h"
#define MINIMUM_STEP_AMOUNT 1.0
/**
* pika_display_shell_scrollbars_update:
* @shell:
*
**/
void
pika_display_shell_scrollbars_update (PikaDisplayShell *shell)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
if (! shell->display)
return;
/* Horizontal scrollbar */
g_object_freeze_notify (G_OBJECT (shell->hsbdata));
/* Update upper and lower value before we set the new value */
pika_display_shell_scrollbars_setup_horizontal (shell, shell->offset_x);
g_object_set (shell->hsbdata,
"value", (gdouble) shell->offset_x,
"page-size", (gdouble) shell->disp_width,
"page-increment", (gdouble) shell->disp_width / 2,
NULL);
g_object_thaw_notify (G_OBJECT (shell->hsbdata)); /* emits "changed" */
/* Vertcal scrollbar */
g_object_freeze_notify (G_OBJECT (shell->vsbdata));
/* Update upper and lower value before we set the new value */
pika_display_shell_scrollbars_setup_vertical (shell, shell->offset_y);
g_object_set (shell->vsbdata,
"value", (gdouble) shell->offset_y,
"page-size", (gdouble) shell->disp_height,
"page-increment", (gdouble) shell->disp_height / 2,
NULL);
g_object_thaw_notify (G_OBJECT (shell->vsbdata)); /* emits "changed" */
}
/**
* pika_display_shell_scrollbars_setup_horizontal:
* @shell:
* @value:
*
* Setup the limits of the horizontal scrollbar
**/
void
pika_display_shell_scrollbars_setup_horizontal (PikaDisplayShell *shell,
gdouble value)
{
gint bounds_x;
gint bounds_width;
gint bounding_box_x;
gint bounding_box_width;
gint x1;
gint x2;
gdouble lower;
gdouble upper;
gdouble scale_x;
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
if (! shell->display || ! pika_display_get_image (shell->display))
return;
pika_display_shell_scale_get_image_bounds (shell,
&bounds_x, NULL,
&bounds_width, NULL);
if (! pika_display_shell_get_infinite_canvas (shell))
{
bounding_box_x = bounds_x;
bounding_box_width = bounds_width;
}
else
{
pika_display_shell_scale_get_image_bounding_box (
shell,
&bounding_box_x, NULL,
&bounding_box_width, NULL);
}
x1 = bounding_box_x;
x2 = bounding_box_x + bounding_box_width;
x1 = MIN (x1, bounds_x + bounds_width / 2 - shell->disp_width / 2);
x2 = MAX (x2, bounds_x + bounds_width / 2 + (shell->disp_width + 1) / 2);
lower = MIN (value, x1);
upper = MAX (value + shell->disp_width, x2);
pika_display_shell_get_rotated_scale (shell, &scale_x, NULL);
g_object_set (shell->hsbdata,
"lower", lower,
"upper", upper,
"step-increment", (gdouble) MAX (scale_x, MINIMUM_STEP_AMOUNT),
NULL);
}
/**
* pika_display_shell_scrollbars_setup_vertical:
* @shell:
* @value:
*
* Setup the limits of the vertical scrollbar
**/
void
pika_display_shell_scrollbars_setup_vertical (PikaDisplayShell *shell,
gdouble value)
{
gint bounds_y;
gint bounds_height;
gint bounding_box_y;
gint bounding_box_height;
gint y1;
gint y2;
gdouble lower;
gdouble upper;
gdouble scale_y;
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
if (! shell->display || ! pika_display_get_image (shell->display))
return;
pika_display_shell_scale_get_image_bounds (shell,
NULL, &bounds_y,
NULL, &bounds_height);
if (! pika_display_shell_get_infinite_canvas (shell))
{
bounding_box_y = bounds_y;
bounding_box_height = bounds_height;
}
else
{
pika_display_shell_scale_get_image_bounding_box (
shell,
NULL, &bounding_box_y,
NULL, &bounding_box_height);
}
y1 = bounding_box_y;
y2 = bounding_box_y + bounding_box_height;
y1 = MIN (y1, bounds_y + bounds_height / 2 - shell->disp_height / 2);
y2 = MAX (y2, bounds_y + bounds_height / 2 + (shell->disp_height + 1) / 2);
lower = MIN (value, y1);
upper = MAX (value + shell->disp_height, y2);
pika_display_shell_get_rotated_scale (shell, NULL, &scale_y);
g_object_set (shell->vsbdata,
"lower", lower,
"upper", upper,
"step-increment", (gdouble) MAX (scale_y, MINIMUM_STEP_AMOUNT),
NULL);
}
/**
* pika_display_shell_scrollbars_update_steppers:
* @shell:
* @min_offset_x:
* @max_offset_x:
* @min_offset_y:
* @max_offset_y:
*
* Sets the scrollbars' stepper sensitivity which is set differently
* from its adjustment limits because we support overscrolling.
**/
void
pika_display_shell_scrollbars_update_steppers (PikaDisplayShell *shell,
gint min_offset_x,
gint max_offset_x,
gint min_offset_y,
gint max_offset_y)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
gtk_range_set_lower_stepper_sensitivity (GTK_RANGE (shell->hsb),
min_offset_x < shell->offset_x ?
GTK_SENSITIVITY_ON :
GTK_SENSITIVITY_OFF);
gtk_range_set_upper_stepper_sensitivity (GTK_RANGE (shell->hsb),
max_offset_x > shell->offset_x ?
GTK_SENSITIVITY_ON :
GTK_SENSITIVITY_OFF);
gtk_range_set_lower_stepper_sensitivity (GTK_RANGE (shell->vsb),
min_offset_y < shell->offset_y ?
GTK_SENSITIVITY_ON :
GTK_SENSITIVITY_OFF);
gtk_range_set_upper_stepper_sensitivity (GTK_RANGE (shell->vsb),
max_offset_y > shell->offset_y ?
GTK_SENSITIVITY_ON :
GTK_SENSITIVITY_OFF);
}