Improved movewindow.lua allows for preprocessing of mouse events

Author: nickgammon

lua/movewindow.lua

@@ -6,21 +6,49 @@ Miniwindow drag-to-move functions.
 
 Author: Nick Gammon
 Date:   15th July 2009
+Modified: 16th November 2010 to add preprocessing
 
 
 This module is intended to make it easier to add drag handlers for miniwindows.
 
 It implements the following:
 
-  windowinfo = movewindow.install (win, default_position, flags)  -- find previous location
+  -- find previous location
+     nocheck: if true, don't check if offscreen  (boolean)
+     friends: other windows to move with this one (table)
+     preprocess: preprocessing for mousedown, mouseup etc. (table)
+  
+     Handler names for preprocess table:
+  
+       mousedown       
+       mouseup         
+       mouseover       
+       cancelmouseover 
+       cancelmousedown 
+       dragmove        
+       dragrelease  
+    
+     If any preprocess handler returns true (that is, neither nil nor false) then the default handler
+     in this module is not used. (The miniwindow name is the third argument)
+     
+     function mousedown (flags, id, win)
+        if bit.band (flags, miniwin.hotspot_got_rh_mouse) then
+          -- do something different here
+          return true
+        end -- if
+        
+        return false   -- take normal movewindow behaviour
+     end -- mousedown 
+
+  windowinfo = movewindow.install (win, default_position, default_flags, nocheck, friends, preprocess)
   
   movewindow.add_drag_handler (win, left, top, right, bottom, cursor)   -- add a drag handler for the nominated rectangle
   
   movewindow.save_state (win)  -- saves the miniwindow location to the appropriate variables
   
 It also installs a position-checker that moves the miniwindow into view after 5 seconds, in case
 you resize the main world window, and the window is no longer visible. The 5 seconds are to give
-the main world window's position and size time to stabilize.
+the main world window's position and size time to stabilize. (Unless nocheck is true)
 
 
 Example of use:
@@ -32,7 +60,7 @@ Example of use:
 
   win = GetPluginID ()   -- miniwindow ID
 
-  windowinfo = movewindow.install (win, 7, 0)   -- get position (default to right/middle)
+  windowinfo = movewindow.install (win, miniwin.pos_center_right, 0)  -- default position / flags
   
   -- make miniwindow (use locations returned from last time we saved the state)
   -- note that the width and height are not part of the window position info, and can thus change as required
@@ -52,8 +80,7 @@ Example of use:
    --  in this case we use 0,0,0,0 as the rectangle (ie. the whole window)
    --  typically the height would be the size of the title bar
    
-   movewindow.add_drag_handler (win, 0, 0, 0, 0, 10)  -- both-ways arrow cursor (10)
-
+   movewindow.add_drag_handler (win, 0, 0, 0, 0, miniwin.cursor_both_arrow) 
  
    -- SAVE STATE in OnPluginSaveState
    
@@ -95,8 +122,15 @@ movewindow = {}  -- table to hold functions like movewindow.install
 local function make_mousedown_handler (mwi)
 
   return function (flags, hotspot_id)
-
+   
     local win = mwi.win
+       
+    -- see if other action wanted
+    if mwi.preprocess.mousedown then
+      if mwi.preprocess.mousedown (flags, hotspot_id, win) then
+         return
+      end -- if handled already
+    end -- if handler
 
     -- find where mouse is so we can adjust window relative to mouse
     mwi.startx = WindowInfo (win, 14)
@@ -107,9 +141,13 @@ local function make_mousedown_handler (mwi)
     mwi.origy = WindowInfo (win, 11)
 
     -- find where the friends are relative to the window
-    for i,v in ipairs(mwi.window_friends) do
-        if (v ~= nil) then
-            mwi.window_friend_deltas[i] = {WindowInfo(v, 10) - mwi.origx, WindowInfo(v, 11) - mwi.origy}
+    for i, v in ipairs (mwi.window_friends) do
+        if v then
+            mwi.window_friend_deltas [i] = 
+               {
+               WindowInfo (v, 10) - mwi.origx, 
+               WindowInfo (v, 11) - mwi.origy
+               }
         end -- if
     end -- for
 
@@ -125,17 +163,27 @@ local function make_dragmove_handler (mwi)
 
     local win = mwi.win
 
+    -- see if other action wanted
+    if mwi.preprocess.dragmove then
+      if mwi.preprocess.dragmove (flags, hotspot_id, win) then
+         return
+      end -- if handled already
+    end -- if handler
+    
     -- find where it is now
     local posx, posy = WindowInfo (win, 17) - mwi.startx,
                        WindowInfo (win, 18) - mwi.starty
 
     -- move the window to the new location - offset by how far mouse was into window
-    WindowPosition(win, posx, posy, 0, 2);
+    WindowPosition(win, posx, posy, 0, miniwin.create_absolute_location);
 
     -- move the friends if they still exist
-    for i,v in ipairs(mwi.window_friends) do
-        if (v ~= nil) then
-            WindowPosition(v, posx+mwi.window_friend_deltas[i][1], posy+mwi.window_friend_deltas[i][2], 0, WindowInfo(v, 8))
+    for i, v in ipairs(mwi.window_friends) do
+        if v then
+            WindowPosition (v, posx + mwi.window_friend_deltas [i] [1], 
+                               posy + mwi.window_friend_deltas [i] [2], 
+                               0, 
+                               WindowInfo (v, 8))
         end -- if
     end -- for
 
@@ -144,15 +192,15 @@ local function make_dragmove_handler (mwi)
        posx > GetInfo (281) - mwi.margin or
        posy < 0 or   -- don't drag title out of view
        posy > GetInfo (280) - mwi.margin then
-      SetCursor (11)   -- X cursor
+      SetCursor (miniwin.cursor_x)   -- X cursor
     else
-      SetCursor (1)    -- hand cursor
+      SetCursor (miniwin.cursor_hand)    -- hand cursor
     end -- if
 
     mwi.window_left = posx  -- remember for saving state
     mwi.window_top = posy
     mwi.window_mode = 0
-    mwi.window_flags = 2   -- absolute position
+    mwi.window_flags = miniwin.create_absolute_location   -- absolute position
 
   end -- dragmove
 
@@ -166,6 +214,13 @@ local function make_dragrelease_handler (mwi)
 
     local win = mwi.win
 
+    -- see if other action wanted
+    if mwi.preprocess.dragrelease then
+      if mwi.preprocess.dragrelease (flags, hotspot_id, win) then
+         return
+      end -- if handled already
+    end -- if handler
+    
     Repaint ()  -- update window location
 
     -- find where window is now
@@ -177,12 +232,12 @@ local function make_dragrelease_handler (mwi)
        newy < 0 or  -- don't drag title out of view
        newy > GetInfo (280) - mwi.margin then
        -- put it back
-      WindowPosition(win, mwi.origx, mwi.origy, 0, 2)
+      WindowPosition(win, mwi.origx, mwi.origy, 0, miniwin.create_absolute_location)
 
       mwi.window_left = mwi.origx  -- remember for saving state
       mwi.window_top = mwi.origy
       mwi.window_mode = 0
-      mwi.window_flags = 2   -- absolute position
+      mwi.window_flags = miniwin.create_absolute_location   -- absolute position
 
       return
     end -- if out of bounds
@@ -192,6 +247,21 @@ local function make_dragrelease_handler (mwi)
 
 end -- make_dragrelease_handler  
 
+-- make other handler with the movement information as an upvalue
+
+local function make_other_handler (mwi, name)
+
+  return function (flags, hotspot_id)
+       
+    -- send to supplied handler
+    if mwi.preprocess [name] then
+       mwi.preprocess [name] (flags, hotspot_id, mwi.win)
+    end -- if handler
+        
+  end -- other
+
+end -- make_other_handler
+
 -- make a mouse position-checking function with the movement information as an upvalue
 
 local function make_check_map_position_handler (mwi)
@@ -210,8 +280,8 @@ local function make_check_map_position_handler (mwi)
          mwi.window_left > GetInfo (281) - mwi.margin or
          mwi.window_top < 0 or -- don't drag title out of view
          mwi.window_top > GetInfo (280) - mwi.margin then
-           mwi.window_left, mwi.window_top = 0, 0  -- reset to top left
-           mwi.window_mode = 7
+           mwi.window_left, mwi.window_top = 0, 0  -- reset to center right
+           mwi.window_mode = miniwin.pos_center_right
            mwi.window_flags = 0
       end -- if not visible
 
@@ -228,17 +298,14 @@ end -- make_check_map_position_handler
 -- call movewindow.install in OnPluginInstall to find the position of the window, before creating it
 --  - it also creates the handler functions ready for use later
 
-function movewindow.install (win, default_position, default_flags, nocheck, default_friends)
+function movewindow.install (win, default_position, default_flags, nocheck, friends, preprocess)
 
   win = win or GetPluginID ()  -- default to current plugin ID
 
   assert (not string.match (win, "[^A-Za-z0-9_]"), "Invalid window name in movewindow.install: " .. win)
 
-  default_position = default_position or 7 -- on right, center top/bottom
+  default_position = default_position or miniwin.pos_center_right -- on right, center top/bottom
   default_flags = default_flags or 0
-  if (default_friends == nil) then
-    default_friends = {}
-  end
 
   -- set up handlers and where window should be shown (from saved state, if any)
   local movewindow_info = {
@@ -249,18 +316,28 @@ function movewindow.install (win, default_position, default_flags, nocheck, defa
      window_top   = tonumber (GetVariable ("mw_" .. win .. "_windowy")) or 0,
      window_mode  = tonumber (GetVariable ("mw_" .. win .. "_windowmode")) or default_position,
      window_flags = tonumber (GetVariable ("mw_" .. win .. "_windowflags")) or default_flags,
-     window_friends = default_friends,
+     window_friends = friends or {},
      window_friend_deltas = {},
-     margin = 20  -- how close we can put to the edge of the window
+     margin = 20,  -- how close we can put to the edge of the window
+     preprocess = preprocess or {},
     }
 
+    -- check valid
+    for k, v in pairs (movewindow_info.preprocess) do
+       assert (type (v) == "function", "Handler '" .. k .. "' is not a function")
+    end -- for
+    
     -- handler to reposition window
     movewindow_info.check_map_position = make_check_map_position_handler (movewindow_info)  -- for startup
 
     -- mouse handlers
-    movewindow_info.mousedown   = make_mousedown_handler   (movewindow_info)  
-    movewindow_info.dragmove    = make_dragmove_handler    (movewindow_info)
-    movewindow_info.dragrelease = make_dragrelease_handler (movewindow_info)
+    movewindow_info.mousedown       = make_mousedown_handler   (movewindow_info)  
+    movewindow_info.mouseup         = make_other_handler       (movewindow_info, "mouseup")
+    movewindow_info.mouseover       = make_other_handler       (movewindow_info, "mouseover")
+    movewindow_info.cancelmouseover = make_other_handler       (movewindow_info, "cancelmouseover")
+    movewindow_info.cancelmousedown = make_other_handler       (movewindow_info, "cancelmousedown")
+    movewindow_info.dragmove        = make_dragmove_handler    (movewindow_info)
+    movewindow_info.dragrelease     = make_dragrelease_handler (movewindow_info)
 
   -- save table in global namespace
   _G ["mw_" .. win .. "_movewindow_info"] = movewindow_info
@@ -293,14 +370,14 @@ function movewindow.add_drag_handler (win, left, top, right, bottom, cursor)
 
   -- make a hotspot
   WindowAddHotspot(win, hotspot_id,  
-                   left or 0, top or 0, right or 0, bottom or 0,   -- rectangle
-                   "",   -- MouseOver
-                   "",   -- CancelMouseOver
-                   "mw_" .. win .. "_movewindow_info.mousedown",  -- MouseDown
-                   "",   -- CancelMouseDown
-                   "",   -- MouseUp
+                   left or 0, top or 0, right or 0, bottom or 0,        -- rectangle
+                   "mw_" .. win .. "_movewindow_info.mouseover",        -- MouseOver
+                   "mw_" .. win .. "_movewindow_info.cancelmouseover",  -- CancelMouseOver
+                   "mw_" .. win .. "_movewindow_info.mousedown",        -- MouseDown
+                   "mw_" .. win .. "_movewindow_info.cancelmousedown",  -- CancelMouseDown
+                   "mw_" .. win .. "_movewindow_info.mouseup",          -- MouseUp
                    "Drag to move window",  -- tooltip text
-                   cursor or 1, -- cursor
+                   cursor or miniwin.cursor_hand, -- cursor
                    0)  -- flags
 
   WindowDragHandler (win, hotspot_id,