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gimp/app/display/gimpdisplayshell-scroll.c

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/* GIMP - The GNU Image Manipulation Program
* 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 <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <stdlib.h>
#include <math.h>
#include <gegl.h>
#include <gtk/gtk.h>
#include "libgimpmath/gimpmath.h"
#include "display-types.h"
#include "config/gimpdisplayconfig.h"
#include "core/gimpimage.h"
#include "gimpcanvas.h"
#include "gimpdisplay.h"
#include "gimpdisplay-foreach.h"
#include "gimpdisplayshell.h"
#include "gimpdisplayshell-expose.h"
#include "gimpdisplayshell-rotate.h"
#include "gimpdisplayshell-rulers.h"
#include "gimpdisplayshell-scale.h"
#include "gimpdisplayshell-scroll.h"
#include "gimpdisplayshell-scrollbars.h"
#include "gimpdisplayshell-transform.h"
#define OVERPAN_FACTOR 0.5
/**
* gimp_display_shell_scroll:
* @shell:
* @x_offset:
* @y_offset:
*
* This function scrolls the image in the shell's viewport. It does
* actual scrolling of the pixels, so only the newly scrolled-in parts
* are freshly redrawn.
*
* Use it for incremental actual panning.
**/
void
gimp_display_shell_scroll (GimpDisplayShell *shell,
gint x_offset,
gint y_offset)
{
gint old_x;
gint old_y;
g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
if (x_offset == 0 && y_offset == 0)
return;
old_x = shell->offset_x;
old_y = shell->offset_y;
/* freeze the active tool */
gimp_display_shell_pause (shell);
shell->offset_x += x_offset;
shell->offset_y += y_offset;
gimp_display_shell_scroll_clamp_and_update (shell);
/* the actual changes in offset */
x_offset = (shell->offset_x - old_x);
y_offset = (shell->offset_y - old_y);
if (x_offset || y_offset)
{
gimp_display_shell_scrolled (shell);
gimp_overlay_box_scroll (GIMP_OVERLAY_BOX (shell->canvas),
-x_offset, -y_offset);
}
/* re-enable the active tool */
gimp_display_shell_resume (shell);
}
/**
* gimp_display_shell_scroll_set_offsets:
* @shell:
* @offset_x:
* @offset_y:
*
* This function scrolls the image in the shell's viewport. It redraws
* the entire canvas.
*
* Use it for setting the scroll offset on freshly scaled images or
* when the window is resized. For panning, use
* gimp_display_shell_scroll().
**/
void
gimp_display_shell_scroll_set_offset (GimpDisplayShell *shell,
gint offset_x,
gint offset_y)
{
g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
if (shell->offset_x == offset_x &&
shell->offset_y == offset_y)
return;
gimp_display_shell_scale_save_revert_values (shell);
/* freeze the active tool */
gimp_display_shell_pause (shell);
shell->offset_x = offset_x;
shell->offset_y = offset_y;
gimp_display_shell_scroll_clamp_and_update (shell);
gimp_display_shell_scrolled (shell);
gimp_display_shell_expose_full (shell);
/* re-enable the active tool */
gimp_display_shell_resume (shell);
}
/**
* gimp_display_shell_scroll_clamp_and_update:
* @shell:
*
* Helper function for calling two functions that are commonly called
* in pairs.
**/
void
gimp_display_shell_scroll_clamp_and_update (GimpDisplayShell *shell)
{
GimpImage *image;
g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
image = gimp_display_get_image (shell->display);
if (image)
{
gint bounds_x;
gint bounds_y;
gint bounds_width;
gint bounds_height;
gint min_offset_x;
gint max_offset_x;
gint min_offset_y;
gint max_offset_y;
gint offset_x;
gint offset_y;
gimp_display_shell_rotate_update_transform (shell);
gimp_display_shell_scale_get_image_bounds (shell,
&bounds_x, &bounds_y,
&bounds_width, &bounds_height);
if (shell->disp_width < bounds_width)
{
min_offset_x = bounds_x -
shell->disp_width * OVERPAN_FACTOR;
max_offset_x = bounds_x + bounds_width -
shell->disp_width * (1.0 - OVERPAN_FACTOR);
}
else
{
gint overpan_amount;
overpan_amount = shell->disp_width -
bounds_width * (1.0 - OVERPAN_FACTOR);
min_offset_x = bounds_x -
overpan_amount;
max_offset_x = bounds_x + bounds_width - shell->disp_width +
overpan_amount;
}
if (shell->disp_height < bounds_height)
{
min_offset_y = bounds_y -
shell->disp_height * OVERPAN_FACTOR;
max_offset_y = bounds_y + bounds_height -
shell->disp_height * (1.0 - OVERPAN_FACTOR);
}
else
{
gint overpan_amount;
overpan_amount = shell->disp_height -
bounds_height * (1.0 - OVERPAN_FACTOR);
min_offset_y = bounds_y -
overpan_amount;
max_offset_y = bounds_y + bounds_height +
overpan_amount - shell->disp_height;
}
/* Clamp */
offset_x = CLAMP (shell->offset_x, min_offset_x, max_offset_x);
offset_y = CLAMP (shell->offset_y, min_offset_y, max_offset_y);
if (offset_x != shell->offset_x || offset_y != shell->offset_y)
{
shell->offset_x = offset_x;
shell->offset_y = offset_y;
gimp_display_shell_rotate_update_transform (shell);
}
/* Set scrollbar stepper sensitiity */
gimp_display_shell_scrollbars_update_steppers (shell,
min_offset_x,
max_offset_x,
min_offset_y,
max_offset_y);
}
else
{
shell->offset_x = 0;
shell->offset_y = 0;
}
gimp_display_shell_scrollbars_update (shell);
gimp_display_shell_rulers_update (shell);
}
/**
* gimp_display_shell_scroll_unoverscrollify:
* @shell:
* @in_offset_x:
* @in_offset_y:
* @out_offset_x:
* @out_offset_y:
*
* Takes a scroll offset and returns the offset that will not result
* in a scroll beyond the image border. If the image is already
* overscrolled, the return value is 0 for that given axis.
**/
void
gimp_display_shell_scroll_unoverscrollify (GimpDisplayShell *shell,
gint in_offset_x,
gint in_offset_y,
gint *out_offset_x,
gint *out_offset_y)
{
gint sw, sh;
gint out_offset_x_dummy, out_offset_y_dummy;
g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
if (! out_offset_x) out_offset_x = &out_offset_x_dummy;
if (! out_offset_y) out_offset_y = &out_offset_y_dummy;
*out_offset_x = in_offset_x;
*out_offset_y = in_offset_y;
gimp_display_shell_scale_get_image_size (shell, &sw, &sh);
if (in_offset_x < 0)
{
*out_offset_x = MAX (in_offset_x,
MIN (0, 0 - shell->offset_x));
}
else if (in_offset_x > 0)
{
gint min_offset = sw - shell->disp_width;
*out_offset_x = MIN (in_offset_x,
MAX (0, min_offset - shell->offset_x));
}
if (in_offset_y < 0)
{
*out_offset_y = MAX (in_offset_y,
MIN (0, 0 - shell->offset_y));
}
else if (in_offset_y > 0)
{
gint min_offset = sh - shell->disp_height;
*out_offset_y = MIN (in_offset_y,
MAX (0, min_offset - shell->offset_y));
}
}
/**
* gimp_display_shell_scroll_center_image_xy:
* @shell:
* @image_x:
* @image_y:
*
* Center the viewport around the passed image coordinate
**/
void
gimp_display_shell_scroll_center_image_xy (GimpDisplayShell *shell,
gdouble image_x,
gdouble image_y)
{
gint viewport_x;
gint viewport_y;
gimp_display_shell_transform_xy (shell,
image_x, image_y,
&viewport_x, &viewport_y);
gimp_display_shell_scroll (shell,
viewport_x - shell->disp_width / 2,
viewport_y - shell->disp_height / 2);
}
/**
* gimp_display_shell_scroll_center_image:
* @shell:
* @horizontally:
* @vertically:
*
* Centers the image in the display shell on the desired axes.
**/
void
gimp_display_shell_scroll_center_image (GimpDisplayShell *shell,
gboolean horizontally,
gboolean vertically)
{
gint image_x;
gint image_y;
gint image_width;
gint image_height;
gint center_x;
gint center_y;
gint offset_x = 0;
gint offset_y = 0;
g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
if (! shell->display ||
! gimp_display_get_image (shell->display) ||
(! vertically && ! horizontally))
return;
gimp_display_shell_scale_get_image_bounds (shell,
&image_x, &image_y,
&image_width, &image_height);
if (shell->disp_width > image_width)
{
image_x -= (shell->disp_width - image_width) / 2;
image_width = shell->disp_width;
}
if (shell->disp_height > image_height)
{
image_y -= (shell->disp_height - image_height) / 2;
image_height = shell->disp_height;
}
center_x = image_x + image_width / 2;
center_y = image_y + image_height / 2;
if (horizontally)
offset_x = center_x - shell->disp_width / 2 - shell->offset_x;
if (vertically)
offset_y = center_y - shell->disp_height / 2 - shell->offset_y;
gimp_display_shell_scroll (shell, offset_x, offset_y);
}
typedef struct
{
GimpDisplayShell *shell;
gboolean vertically;
gboolean horizontally;
} CenterImageData;
static void
gimp_display_shell_scroll_center_image_callback (GtkWidget *canvas,
GtkAllocation *allocation,
CenterImageData *data)
{
g_signal_handlers_disconnect_by_func (canvas,
gimp_display_shell_scroll_center_image_callback,
data);
gimp_display_shell_scroll_center_image (data->shell,
data->horizontally,
data->vertically);
g_slice_free (CenterImageData, data);
}
/**
* gimp_display_shell_scroll_center_image_on_size_allocate:
* @shell:
*
* Centers the image in the display as soon as the canvas has got its
* new size.
*
* Only call this if you are sure the canvas size will change.
* (Otherwise the signal connection and centering will lurk until the
* canvas size is changed e.g. by toggling the rulers.)
**/
void
gimp_display_shell_scroll_center_image_on_size_allocate (GimpDisplayShell *shell,
gboolean horizontally,
gboolean vertically)
{
CenterImageData *data;
g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
data = g_slice_new (CenterImageData);
data->shell = shell;
data->horizontally = horizontally;
data->vertically = vertically;
g_signal_connect (shell->canvas, "size-allocate",
G_CALLBACK (gimp_display_shell_scroll_center_image_callback),
data);
}
/**
* gimp_display_shell_scroll_get_scaled_viewport:
* @shell:
* @x:
* @y:
* @w:
* @h:
*
* Gets the viewport in screen coordinates, with origin at (0, 0) in
* the image.
**/
void
gimp_display_shell_scroll_get_scaled_viewport (GimpDisplayShell *shell,
gint *x,
gint *y,
gint *w,
gint *h)
{
g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
*x = shell->offset_x;
*y = shell->offset_y;
*w = shell->disp_width;
*h = shell->disp_height;
}
/**
* gimp_display_shell_scroll_get_viewport:
* @shell:
* @x:
* @y:
* @w:
* @h:
*
* Gets the viewport in image coordinates.
**/
void
gimp_display_shell_scroll_get_viewport (GimpDisplayShell *shell,
gdouble *x,
gdouble *y,
gdouble *w,
gdouble *h)
{
g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
*x = shell->offset_x / shell->scale_x;
*y = shell->offset_y / shell->scale_y;
*w = shell->disp_width / shell->scale_x;
*h = shell->disp_height / shell->scale_y;
}
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