Functions to change client focus by direction across screens

Added functions awful.client.focus.global_bydirection and
awful.client.swap.global_bydirection, that change focus and swap clients,
crossing screen boundaries.

Also modified awful.client.movetoscreen. Now calls awful.screen.focus.

Signed-off-by: Uli Schlachter <psychon@znc.in>

lib/awful/client.lua.in

@@ -252,95 +252,54 @@ function client.next(i, c)
     end
 end
 
--- Return true whether client B is in the right direction
--- compared to client A.
--- @param dir The direction.
--- @param cA The first client.
--- @param cB The second client.
--- @return True if B is in the direction of A.
-local function is_in_direction(dir, cA, cB)
-    local gA = cA:geometry()
-    local gB = cB:geometry()
-    if dir == "up" then
-        return gA.y > gB.y
-    elseif dir == "down" then
-        return gA.y < gB.y
-    elseif dir == "left" then
-        return gA.x > gB.x
-    elseif dir == "right" then
-        return gA.x < gB.x
-    end
-    return false
-end
-
--- Calculate distance between two points.
--- i.e: if we want to move to the right, we will take the right border
--- of the currently focused client and the left side of the checked client.
--- This avoid the focus of an upper client when you move to the right in a
--- tilebottom layout with nmaster=2 and 5 clients open, for instance.
--- @param dir The direction.
--- @param cA The first client.
--- @param cB The second client.
--- @return The distance between the clients.
-local function calculate_distance(dir, cA, cB)
-    local gA = cA:geometry()
-    local gB = cB:geometry()
-
-    if dir == "up" then
-        gB.y = gB.y + gB.height
-    elseif dir == "down" then
-        gA.y = gA.y + gA.height
-    elseif dir == "left" then
-        gB.x = gB.x + gB.width
-    elseif dir == "right" then
-        gA.x = gA.x + gA.width
-    end
-
-    return math.sqrt(math.pow(gB.x - gA.x, 2) + math.pow(gB.y - gA.y, 2))
-end
-
--- Get the nearest client in the given direction.
--- @param dir The direction, can be either "up", "down", "left" or "right".
--- @param c Optional client to get a client relative to. Else focussed is used.
-local function get_client_in_direction(dir, c)
-    local sel = c or capi.client.focus
-    if sel then
-        local geometry = sel:geometry()
-        local dist, dist_min
-        local target = nil
-        local cls = client.visible(sel.screen)
-
-        -- We check each client.
-        for i, c in ipairs(cls) do
-            -- Check geometry to see if client is located in the right direction.
-            if is_in_direction(dir, sel, c) then
-
-                -- Calculate distance between focused client and checked client.
-                dist = calculate_distance(dir, sel, c)
-
-                -- If distance is shorter then keep the client.
-                if not target or dist < dist_min then
-                    target = c
-                    dist_min = dist
-                end
-            end
-        end
-
-        return target
-    end
-end
-
 --- Focus a client by the given direction.
 -- @param dir The direction, can be either "up", "down", "left" or "right".
 -- @param c Optional client.
 function client.focus.bydirection(dir, c)
     local sel = c or capi.client.focus
     if sel then
-        local target = get_client_in_direction(dir, sel)
+        local cltbl = client.visible(sel.screen)
+        local geomtbl = {}
+        for i,cl in ipairs(cltbl) do
+            geomtbl[i] = cl:geometry()
+        end
+
+        local target = util.get_rectangle_in_direction(dir, geomtbl, sel:geometry())
 
         -- If we found a client to focus, then do it.
         if target then
-            capi.client.focus = target
+            capi.client.focus = cltbl[target]
+        end
+    end
+end
+
+--- Focus a client by the given direction. Moves across screens.
+-- @param dir The direction, can be either "up", "down", "left" or "right".
+-- @param c Optional client.
+function client.focus.global_bydirection(dir, c)
+    local sel = c or capi.client.focus
+    local scr = capi.mouse.screen
+    if sel then
+        scr = sel.screen
+    end
+
+    -- change focus inside the screen
+    client.focus.bydirection(dir, sel)
+
+    -- if focus not changed, we must change screen
+    if sel == capi.client.focus then
+        awful.screen.focus_bydirection(dir, scr)
+        if scr ~= capi.mouse.screen then
+            local cltbl = client.visible(capi.mouse.screen)
+            local geomtbl = {}
+            for i,cl in ipairs(cltbl) do
+                geomtbl[i] = cl:geometry()
+            end
+            local target = util.get_rectangle_in_direction(dir, geomtbl, capi.screen[scr].geometry)
+
+            if target then
+                capi.client.focus = cltbl[target]
+            end
         end
     end
 end
@@ -361,15 +320,54 @@ end
 function client.swap.bydirection(dir, c)
     local sel = c or capi.client.focus
     if sel then
-        local target = get_client_in_direction(dir, sel)
+        local cltbl = client.visible(sel.screen)
+        local geomtbl = {}
+        for i,cl in ipairs(cltbl) do
+            geomtbl[i] = cl:geometry()
+        end
+        local target = util.get_rectangle_in_direction(dir, geomtbl, sel:geometry())
 
         -- If we found a client to swap with, then go for it
         if target then
-            target:swap(sel)
+            cltbl[target]:swap(sel)
         end
     end
 end
 
+--- Swap a client with another client in the given direction. Swaps across screens.
+-- @param dir The direction, can be either "up", "down", "left" or "right".
+-- @param c Optional client.
+function client.swap.global_bydirection(dir, c)
+    local sel = c or capi.client.focus
+    local screen = capi.mouse.screen
+    if sel then
+        screen = sel.screen
+    end
+
+    if sel then
+        -- move focus
+        client.focus.global_bydirection(dir, sel)
+        local c = capi.client.focus
+
+        -- swapping inside a screen
+        if sel.screen == c.screen and sel ~= c then
+            c:swap(sel)
+
+        -- swapping to an empty screen
+        elseif sel.screen ~= c.screen and sel == c then
+	    awful.client.movetoscreen(sel, capi.mouse.screen)
+
+        --swapping to a nonempty screen
+        elseif sel.screen ~= c.screen and sel ~= c then
+	    awful.client.movetoscreen(sel, c.screen)
+            awful.client.movetoscreen(c, screen)
+        end
+
+        awful.screen.focus(sel.screen)
+        capi.client.focus = sel
+    end
+end
+
 --- Swap a client by its relative index.
 -- @param i The index.
 -- @param c Optional client, otherwise focused one is used.
@@ -494,7 +492,7 @@ function client.movetoscreen(c, s)
         end
         if s > sc then s = 1 elseif s < 1 then s = sc end
         sel.screen = s
-        capi.mouse.coords(capi.screen[s].geometry)
+        awful.screen.focus(s)
     end
 end