[Freeciv-Dev] Re: (PR#3726) Scroll map witth arrow keys

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

a-l@xxxxxxx wrote:
> Parent: (PR#3529) Map Control patch
> 
> On Sun, 2 Mar 2003 01:41:50 -0800
> "Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx> wrote:
> 
> 
>>One of the small features is the keyboard map scrolling.  A few thoughts
>>on that:
> 
> 
>>Seems like this would be more easily done in pixel coordinates. 
>>Something like:
>>
>>  get_center_tile_mapcanvas(&map_x, &map_y);
>>  map_to_canvas_pos(&canvas_x, &canvas_y, map_x, map_y);
>>  canvas_x += DIR_DX[dir] * mapview_canvas.width / 2;
>>  canvas_y += DIR_DY[dir] * mapview_canvas.height / 2;
>>  canvas_to_map_pos(&map_x, &map_y, canvas_x, canvas_y);
>>  center_tile_mapcanvas(map_x, map_y);
> 
> 
> That was very elegant. New standalone patch, for GTK1 and GTK2.

Here's a slightly changed patch:

- scroll_map renamed to scroll_mapview.
- use can_client_change_view() to determine if the command is valid.
- Don't call get_center_tile_mapcanvas; this is unnecessary.
- Rename 'dir' parameter as gui_dir.
- Add a comment to the function.

There are three problems:

- Ross would say this is a misuse of DIR_DX/DIR_DY.  And he'd be right.

- Ross would say this is a use of enum direction8, although I disagree 
on this.

- Because of PR#2412 the scrolling does not work quite the way it should 
(which is a reason to fix 2412).

I do think this function provides a nice framework for future work on 
auto-scrolling.  For instance gui-sdl in fullscreen mode should 
(optionally) scroll the mapview when the mouse reaches the border - with 
varying speed and range (which is not yet implemented).

jason

Index: client/mapctrl_common.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/mapctrl_common.c,v
retrieving revision 1.5
diff -u -r1.5 mapctrl_common.c
--- client/mapctrl_common.c     2003/01/09 19:21:17     1.5
+++ client/mapctrl_common.c     2003/03/15 00:27:39
@@ -43,6 +43,26 @@
 }
 
 /**************************************************************************
+  Scroll the mapview half a screen in the given direction.  This is a GUI
+  direction; i.e., DIR8_NORTH is "up" on the mapview.
+**************************************************************************/
+void scroll_mapview(enum direction8 gui_dir)
+{
+  int map_x, map_y, canvas_x, canvas_y;
+
+  if (!can_client_change_view()) {
+    return;
+  }
+
+  canvas_x = mapview_canvas.width / 2;
+  canvas_y = mapview_canvas.height / 2;
+  canvas_x += DIR_DX[gui_dir] * mapview_canvas.width / 2;
+  canvas_y += DIR_DY[gui_dir] * mapview_canvas.height / 2;
+  get_map_xy(canvas_x, canvas_y, &map_x, &map_y);
+  center_tile_mapcanvas(map_x, map_y);
+}
+
+/**************************************************************************
  Update the turn done button state.
 **************************************************************************/
 void update_turn_done_button_state()
Index: client/mapctrl_common.h
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/mapctrl_common.h,v
retrieving revision 1.2
diff -u -r1.2 mapctrl_common.h
--- client/mapctrl_common.h     2003/01/09 19:21:17     1.2
+++ client/mapctrl_common.h     2003/03/15 00:27:39
@@ -17,6 +17,7 @@
 #include "shared.h"            /* bool type */
 
 bool get_turn_done_button_state(void);
+void scroll_mapview(enum direction8 gui_dir);
 void update_turn_done_button_state(void);
 void update_line(int canvas_x, int canvas_y);
 
Index: client/gui-gtk/gui_main.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/gui-gtk/gui_main.c,v
retrieving revision 1.130
diff -u -r1.130 gui_main.c
--- client/gui-gtk/gui_main.c   2003/02/26 19:00:36     1.130
+++ client/gui-gtk/gui_main.c   2003/03/15 00:27:40
@@ -246,7 +246,6 @@
 
   if (!client_is_observer()) {
     switch (ev->keyval) {
-      case GDK_Up:
       case GDK_KP_Up:
       case GDK_8:
       case GDK_KP_8:
@@ -260,7 +259,6 @@
        key_unit_move(DIR8_NORTHEAST);
        break;
 
-      case GDK_Right:
       case GDK_KP_Right:
       case GDK_6:
       case GDK_KP_6:
@@ -274,7 +272,6 @@
        key_unit_move(DIR8_SOUTHEAST);
        break;
 
-      case GDK_Down:
       case GDK_KP_Down:
       case GDK_2:
       case GDK_KP_2:
@@ -288,7 +285,6 @@
        key_unit_move(DIR8_SOUTHWEST);
        break;
 
-      case GDK_Left:
       case GDK_KP_Left:
       case GDK_4:
       case GDK_KP_4:
@@ -301,6 +297,22 @@
       case GDK_KP_7:
        key_unit_move(DIR8_NORTHWEST);
        break;
+
+      case GDK_Left:
+        scroll_mapview(DIR8_WEST);
+        break;
+
+      case GDK_Right:
+        scroll_mapview(DIR8_EAST);
+        break;
+
+      case GDK_Up:
+        scroll_mapview(DIR8_NORTH);
+        break;
+
+      case GDK_Down:
+        scroll_mapview(DIR8_SOUTH);
+        break;
 
       case GDK_KP_Begin:
       case GDK_Return:
Index: client/gui-gtk-2.0/gui_main.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/client/gui-gtk-2.0/gui_main.c,v
retrieving revision 1.46
diff -u -r1.46 gui_main.c
--- client/gui-gtk-2.0/gui_main.c       2003/03/02 17:43:16     1.46
+++ client/gui-gtk-2.0/gui_main.c       2003/03/15 00:27:40
@@ -370,7 +370,6 @@
 
   if (!client_is_observer()) {
     switch (ev->keyval) {
-      case GDK_Up:
       case GDK_KP_Up:
       case GDK_8:
       case GDK_KP_8:
@@ -384,7 +383,6 @@
        key_unit_move(DIR8_NORTHEAST);
        break;
 
-      case GDK_Right:
       case GDK_KP_Right:
       case GDK_6:
       case GDK_KP_6:
@@ -398,7 +396,6 @@
        key_unit_move(DIR8_SOUTHEAST);
        break;
 
-      case GDK_Down:
       case GDK_KP_Down:
       case GDK_2:
       case GDK_KP_2:
@@ -412,7 +409,6 @@
        key_unit_move(DIR8_SOUTHWEST);
        break;
 
-      case GDK_Left:
       case GDK_KP_Left:
       case GDK_4:
       case GDK_KP_4:
@@ -425,6 +421,22 @@
       case GDK_KP_7:
        key_unit_move(DIR8_NORTHWEST);
        break;
+
+      case GDK_Left:
+        scroll_mapview(DIR8_WEST);
+        break;
+
+      case GDK_Right:
+        scroll_mapview(DIR8_EAST);
+        break;
+
+      case GDK_Up:
+        scroll_mapview(DIR8_NORTH);
+        break;
+
+      case GDK_Down:
+        scroll_mapview(DIR8_SOUTH);
+        break;
 
       case GDK_KP_Begin:
       case GDK_Return: