1 files changed, 184 insertions, 0 deletions
diff --git a/app/display/gimpdisplayshell-autoscroll.c b/app/display/gimpdisplayshell-autoscroll.c
new file mode 100644
index 0000000..39cf252
--- /dev/null
+++ b/app/display/gimpdisplayshell-autoscroll.c
@@ -0,0 +1,184 @@
+/* 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 <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "widgets/gimpdeviceinfo.h"
+#include "widgets/gimpdeviceinfo-coords.h"
+
+#include "gimpdisplay.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-autoscroll.h"
+#include "gimpdisplayshell-scroll.h"
+#include "gimpdisplayshell-transform.h"
+
+#include "tools/tools-types.h"
+#include "tools/tool_manager.h"
+#include "tools/gimptool.h"
+#include "tools/gimptoolcontrol.h"
+
+
+#define AUTOSCROLL_DT  20
+#define AUTOSCROLL_DX  0.1
+
+
+typedef struct
+{
+  GdkEventMotion  *mevent;
+  GimpDeviceInfo  *device;
+  guint32          time;
+  GdkModifierType  state;
+  guint            timeout_id;
+} ScrollInfo;
+
+
+/*  local function prototypes  */
+
+static gboolean gimp_display_shell_autoscroll_timeout (gpointer data);
+
+
+/*  public functions  */
+
+void
+gimp_display_shell_autoscroll_start (GimpDisplayShell *shell,
+                                     GdkModifierType   state,
+                                     GdkEventMotion   *mevent)
+{
+  ScrollInfo *info;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (shell->scroll_info)
+    return;
+
+  info = g_slice_new0 (ScrollInfo);
+
+  info->mevent     = mevent;
+  info->device     = gimp_device_info_get_by_device (mevent->device);
+  info->time       = gdk_event_get_time ((GdkEvent *) mevent);
+  info->state      = state;
+  info->timeout_id = g_timeout_add (AUTOSCROLL_DT,
+                                    gimp_display_shell_autoscroll_timeout,
+                                    shell);
+
+  shell->scroll_info = info;
+}
+
+void
+gimp_display_shell_autoscroll_stop (GimpDisplayShell *shell)
+{
+  ScrollInfo *info;
+
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+
+  if (! shell->scroll_info)
+    return;
+
+  info = shell->scroll_info;
+
+  if (info->timeout_id)
+    {
+      g_source_remove (info->timeout_id);
+      info->timeout_id = 0;
+    }
+
+  g_slice_free (ScrollInfo, info);
+  shell->scroll_info = NULL;
+}
+
+
+/*  private functions  */
+
+static gboolean
+gimp_display_shell_autoscroll_timeout (gpointer data)
+{
+  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (data);
+  ScrollInfo       *info  = shell->scroll_info;
+  GimpCoords        device_coords;
+  GimpCoords        image_coords;
+  gint              dx = 0;
+  gint              dy = 0;
+
+  gimp_device_info_get_device_coords (info->device,
+                                      gtk_widget_get_window (shell->canvas),
+                                      &device_coords);
+
+  if (device_coords.x < 0)
+    dx = device_coords.x;
+  else if (device_coords.x > shell->disp_width)
+    dx = device_coords.x - shell->disp_width;
+
+  if (device_coords.y < 0)
+    dy = device_coords.y;
+  else if (device_coords.y > shell->disp_height)
+    dy = device_coords.y - shell->disp_height;
+
+  if (dx || dy)
+    {
+      GimpDisplay *display         = shell->display;
+      GimpTool    *active_tool     = tool_manager_get_active (display->gimp);
+      gint         scroll_amount_x = AUTOSCROLL_DX * dx;
+      gint         scroll_amount_y = AUTOSCROLL_DX * dy;
+
+      info->time += AUTOSCROLL_DT;
+
+      gimp_display_shell_scroll_unoverscrollify (shell,
+                                                 scroll_amount_x,
+                                                 scroll_amount_y,
+                                                 &scroll_amount_x,
+                                                 &scroll_amount_y);
+
+      gimp_display_shell_scroll (shell,
+                                 scroll_amount_x,
+                                 scroll_amount_y);
+
+      gimp_display_shell_untransform_coords (shell,
+                                             &device_coords,
+                                             &image_coords);
+
+      if (gimp_tool_control_get_snap_to (active_tool->control))
+        {
+          gint x, y, width, height;
+
+          gimp_tool_control_get_snap_offsets (active_tool->control,
+                                              &x, &y, &width, &height);
+
+          gimp_display_shell_snap_coords (shell,
+                                          &image_coords,
+                                          x, y, width, height);
+        }
+
+      tool_manager_motion_active (display->gimp,
+                                  &image_coords,
+                                  info->time, info->state,
+                                  display);
+
+      return TRUE;
+    }
+  else
+    {
+      g_slice_free (ScrollInfo, info);
+      shell->scroll_info = NULL;
+
+      return FALSE;
+    }
+}