gimp/app/tools/gimpmagnifytool.c

/* 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 2 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include "config.h"

#include <gtk/gtk.h>

#include "libgimpmath/gimpmath.h"
#include "libgimpwidgets/gimpwidgets.h"

#include "tools-types.h"

#include "core/gimpimage.h"

#include "widgets/gimphelp-ids.h"

#include "display/gimpdisplay.h"
#include "display/gimpdisplayshell.h"
#include "display/gimpdisplayshell-scale.h"

#include "gimpmagnifyoptions.h"
#include "gimpmagnifytool.h"
#include "gimptoolcontrol.h"

#include "gimp-intl.h"


static void   gimp_magnify_tool_button_press   (GimpTool              *tool,
                                                GimpCoords            *coords,
                                                guint32                time,
                                                GdkModifierType        state,
                                                GimpDisplay           *display);
static void   gimp_magnify_tool_button_release (GimpTool              *tool,
                                                GimpCoords            *coords,
                                                guint32                time,
                                                GdkModifierType        state,
                                                GimpButtonReleaseType  release_type,
                                                GimpDisplay           *display);
static void   gimp_magnify_tool_motion         (GimpTool              *tool,
                                                GimpCoords            *coords,
                                                guint32                time,
                                                GdkModifierType        state,
                                                GimpDisplay           *display);
static void   gimp_magnify_tool_modifier_key   (GimpTool              *tool,
                                                GdkModifierType        key,
                                                gboolean               press,
                                                GdkModifierType        state,
                                                GimpDisplay           *display);
static void   gimp_magnify_tool_cursor_update  (GimpTool              *tool,
                                                GimpCoords            *coords,
                                                GdkModifierType        state,
                                                GimpDisplay           *display);

static void   gimp_magnify_tool_draw           (GimpDrawTool          *draw_tool);


G_DEFINE_TYPE (GimpMagnifyTool, gimp_magnify_tool, GIMP_TYPE_DRAW_TOOL)

#define parent_class gimp_magnify_tool_parent_class


void
gimp_magnify_tool_register (GimpToolRegisterCallback  callback,
                            gpointer                  data)
{
  (* callback) (GIMP_TYPE_MAGNIFY_TOOL,
                GIMP_TYPE_MAGNIFY_OPTIONS,
                gimp_magnify_options_gui,
                0,
                "gimp-zoom-tool",
                _("Zoom"),
                _("Zoom Tool: Adjust the zoom level"),
                N_("tool|_Zoom"), "Z",
                NULL, GIMP_HELP_TOOL_ZOOM,
                GIMP_STOCK_TOOL_ZOOM,
                data);
}

static void
gimp_magnify_tool_class_init (GimpMagnifyToolClass *klass)
{
  GimpToolClass     *tool_class      = GIMP_TOOL_CLASS (klass);
  GimpDrawToolClass *draw_tool_class = GIMP_DRAW_TOOL_CLASS (klass);

  tool_class->button_press   = gimp_magnify_tool_button_press;
  tool_class->button_release = gimp_magnify_tool_button_release;
  tool_class->motion         = gimp_magnify_tool_motion;
  tool_class->modifier_key   = gimp_magnify_tool_modifier_key;
  tool_class->cursor_update  = gimp_magnify_tool_cursor_update;

  draw_tool_class->draw      = gimp_magnify_tool_draw;
}

static void
gimp_magnify_tool_init (GimpMagnifyTool *magnify_tool)
{
  GimpTool *tool = GIMP_TOOL (magnify_tool);

  magnify_tool->x = 0;
  magnify_tool->y = 0;
  magnify_tool->w = 0;
  magnify_tool->h = 0;

  gimp_tool_control_set_scroll_lock            (tool->control, TRUE);
  gimp_tool_control_set_handle_empty_image     (tool->control, TRUE);
  gimp_tool_control_set_wants_click            (tool->control, TRUE);
  gimp_tool_control_set_snap_to                (tool->control, FALSE);

  gimp_tool_control_set_cursor                 (tool->control,
                                                GIMP_CURSOR_MOUSE);
  gimp_tool_control_set_tool_cursor            (tool->control,
                                                GIMP_TOOL_CURSOR_ZOOM);
  gimp_tool_control_set_cursor_modifier        (tool->control,
                                                GIMP_CURSOR_MODIFIER_PLUS);
  gimp_tool_control_set_toggle_cursor_modifier (tool->control,
                                                GIMP_CURSOR_MODIFIER_MINUS);
}

static void
gimp_magnify_tool_button_press (GimpTool        *tool,
                                GimpCoords      *coords,
                                guint32          time,
                                GdkModifierType  state,
                                GimpDisplay     *display)
{
  GimpMagnifyTool *magnify = GIMP_MAGNIFY_TOOL (tool);

  magnify->x = coords->x;
  magnify->y = coords->y;
  magnify->w = 0;
  magnify->h = 0;

  gimp_tool_control_activate (tool->control);
  tool->display = display;

  gimp_draw_tool_start (GIMP_DRAW_TOOL (tool), display);
}

static void
gimp_magnify_tool_button_release (GimpTool              *tool,
                                  GimpCoords            *coords,
                                  guint32                time,
                                  GdkModifierType        state,
                                  GimpButtonReleaseType  release_type,
                                  GimpDisplay           *display)
{
  GimpMagnifyTool    *magnify = GIMP_MAGNIFY_TOOL (tool);
  GimpMagnifyOptions *options = GIMP_MAGNIFY_TOOL_GET_OPTIONS (tool);
  GimpDisplayShell   *shell   = GIMP_DISPLAY_SHELL (tool->display->shell);

  gimp_draw_tool_stop (GIMP_DRAW_TOOL (tool));

  gimp_tool_control_halt (tool->control);

  if (release_type != GIMP_BUTTON_RELEASE_CANCEL)
    {
      gdouble x1, y1, x2, y2;
      gdouble width, height;
      gdouble current_scale;
      gdouble new_scale;

      x1     = (magnify->w < 0) ?  magnify->x + magnify->w : magnify->x;
      y1     = (magnify->h < 0) ?  magnify->y + magnify->h : magnify->y;
      width  = (magnify->w < 0) ? -magnify->w : magnify->w;
      height = (magnify->h < 0) ? -magnify->h : magnify->h;
      x2     = x1 + width;
      y2     = y1 + height;

      width  = MAX (1.0, width);
      height = MAX (1.0, height);

      current_scale = gimp_zoom_model_get_factor (shell->zoom);

      if (release_type == GIMP_BUTTON_RELEASE_CLICK ||
          release_type == GIMP_BUTTON_RELEASE_NO_MOTION)
        {
          new_scale = gimp_zoom_model_zoom_step (options->zoom_type,
                                                 current_scale);
        }
      else
        {
          gdouble display_width;
          gdouble display_height;
          gdouble factor = 1.0;

          display_width  = FUNSCALEX (shell, shell->disp_width);
          display_height = FUNSCALEY (shell, shell->disp_height);

          switch (options->zoom_type)
            {
            case GIMP_ZOOM_IN:
              factor = MIN ((display_width  / width),
                            (display_height / height));
              break;

            case GIMP_ZOOM_OUT:
              factor = MAX ((width  / display_width),
                            (height / display_height));
              break;

            default:
              break;
            }

          new_scale = current_scale * factor;
        }

      if (new_scale != current_scale)
        {
          gdouble xres;
          gdouble yres;
          gint    offset_x = 0;
          gint    offset_y = 0;

          gimp_image_get_resolution (display->image, &xres, &yres);

          switch (options->zoom_type)
            {
            case GIMP_ZOOM_IN:
              /*  move the center of the rectangle to the center of the
               *  viewport:
               *
               *  new_offset = center of rectangle in new scale screen coords
               *               including offset
               *               -
               *               center of viewport in screen coords without
               *               offset
               */
              offset_x = RINT (new_scale * ((x1 + x2) / 2.0) *
                               SCREEN_XRES (shell) / xres -
                               (shell->disp_width / 2.0));

              offset_y = RINT (new_scale * ((y1 + y2) / 2.0) *
                               SCREEN_YRES (shell) / yres -
                               (shell->disp_height / 2.0));
              break;

            case GIMP_ZOOM_OUT:
              /*  move the center of the viewport to the center of the
               *  rectangle:
               *
               *  new_offset = center of viewport in new scale screen coords
               *               including offset
               *               -
               *               center of rectangle in screen coords without
               *               offset
               */
              offset_x = RINT (new_scale * UNSCALEX (shell,
                                                     shell->offset_x +
                                                     shell->disp_width / 2.0) *
                               SCREEN_XRES (shell) / xres -
                               (SCALEX (shell, (x1 + x2) / 2.0) -
                                shell->offset_x));

              offset_y = RINT (new_scale * UNSCALEY (shell,
                                                     shell->offset_y +
                                                     shell->disp_height / 2.0) *
                               SCREEN_YRES (shell) / yres -
                               (SCALEY (shell, (y1 + y2) / 2.0) -
                                shell->offset_y));
              break;

            default:
              break;
            }

          gimp_display_shell_scale_by_values (shell,
                                              new_scale,
                                              offset_x, offset_y,
                                              options->auto_resize);
        }
    }
}

static void
gimp_magnify_tool_motion (GimpTool        *tool,
                          GimpCoords      *coords,
                          guint32          time,
                          GdkModifierType  state,
                          GimpDisplay     *display)
{
  GimpMagnifyTool *magnify = GIMP_MAGNIFY_TOOL (tool);

  gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));

  magnify->w = coords->x - magnify->x;
  magnify->h = coords->y - magnify->y;

  gimp_draw_tool_resume (GIMP_DRAW_TOOL (tool));
}

static void
gimp_magnify_tool_modifier_key (GimpTool        *tool,
                                GdkModifierType  key,
                                gboolean         press,
                                GdkModifierType  state,
                                GimpDisplay     *display)
{
  GimpMagnifyOptions *options = GIMP_MAGNIFY_TOOL_GET_OPTIONS (tool);

  if (key == GDK_CONTROL_MASK)
    {
      switch (options->zoom_type)
        {
        case GIMP_ZOOM_IN:
          g_object_set (options, "zoom-type", GIMP_ZOOM_OUT, NULL);
          break;

        case GIMP_ZOOM_OUT:
          g_object_set (options, "zoom-type", GIMP_ZOOM_IN, NULL);
          break;

        default:
          break;
        }
    }
}

static void
gimp_magnify_tool_cursor_update (GimpTool        *tool,
                                 GimpCoords      *coords,
                                 GdkModifierType  state,
                                 GimpDisplay     *display)
{
  GimpMagnifyOptions *options = GIMP_MAGNIFY_TOOL_GET_OPTIONS (tool);

  gimp_tool_control_set_toggled (tool->control,
                                 options->zoom_type == GIMP_ZOOM_OUT);

  GIMP_TOOL_CLASS (parent_class)->cursor_update (tool, coords, state, display);
}

static void
gimp_magnify_tool_draw (GimpDrawTool *draw_tool)
{
  GimpMagnifyTool *magnify = GIMP_MAGNIFY_TOOL (draw_tool);

  gimp_draw_tool_draw_rectangle (draw_tool,
                                 FALSE,
                                 magnify->x,
                                 magnify->y,
                                 magnify->w,
                                 magnify->h,
                                 FALSE);
}