Added Gui.cam_link

ExpCore/gui.lua

@@ -10,6 +10,13 @@ Discord: https://discord.gg/r6dC2uK
 local Gui = {}
 local Gui_data = {}
 
+-- only really used when parts of expcore are missing, or script debuging (ie to store the location of frames)
+function Gui._global(reset)
+    global.exp_core = not reset and global.exp_core or {}
+    global.exp_core.gui = not reset and global.exp_core.gui or {}
+    return global.exp_core.gui
+end
+
 -- this is to enforce the read only propetry of the gui
 function Gui._add_data(key,value_key,value) 
     if game then return end 
@@ -25,6 +32,11 @@ function Gui:_load_parts(parts)
     end
 end
 
+--- Add a white bar to any gui frame
+-- @usage Gui.bar(frame,100)
+-- @param frame the frame to draw the line to
+-- @param[opt=10] width the width of the bar
+-- @return the line that was made type is progressbar
 function Gui.bar(frame,width)
     local line = frame.add{
         type='progressbar',
@@ -37,10 +49,81 @@ function Gui.bar(frame,width)
     return line
 end
 
+local function _thread()
+    local thread = Server.get_thread('camera-follow')
+    if not thread then
+        thread = Server.new_thread{name='camera-follow',data={cams={},cam_index=1}}
+        thread:on_event('tick',function(self) 
+            local _cam = self.data.cams[self.data.cam_index]
+            if not _cam then self.data.cam_index = 1 return end
+            if not _cam.cam.valid then table.remove(self.data.cams,self.data.cam_index)
+            elseif not _cam.entity.valid then table.remove(self.data.cams,self.data.cam_index)
+            else _cam.cam.position = _cam.entity.position if not _cam.surface then _cam.cam.surface_index = _cam.entity.surface.index end self.data.cam_index = self.data.cam_index+1
+            end
+        end)
+        thread:on_event('error',function(self,err)
+            -- posible error handling if needed
+            error(err)
+        end)
+        thread:open()
+    end
+    return thread
+end
+--- Adds a camera that updates every tick (or less depeading on how many are opening) it will move to follow an entity
+-- @usage Gui.cam_link{entity=game.player.character,frame=frame,width=50,hight=50,zoom=1}
+-- @usage Gui.cam_link{entity=game.player.character,cam=frame.camera,surface=game.surfaces['testing']}
+-- @param entity this is the entity that the camera will follow
+-- @param[opt] cam a camera that you already have in the gui
+-- @param[opt] frame the frame to add the camera to, no effect if cam param is given
+-- @param[chain=frame] zoom the zoom to give the new camera
+-- @param[chain=frame] width the width to give the new camera
+-- @param[chain=frame] height the height to give the new camera
+-- @param[opt] surface this will over ride the surface that the camera follows on, allowing for a 'ghost surface' while keeping same position
+-- @return the camera that the function used be it made or given as a param 
+function Gui.cam_link(data)
+    if not data.entity or not data.entity.valid then return end
+    if is_type(data.cam,'table') and data.cam.__self and data.cam.valid then
+        data.cam = data.cam
+    elseif data.frame then
+        data.cam={}
+        data.cam.type='camera'
+        data.cam.name='camera'
+        data.cam.position= data.entity.position
+        data.cam.surface_index= data.surface and data.surface.index or data.entity.surface.index
+        data.cam.zomm = data.zoom
+        data.cam = data.frame.add(data.cam)
+        data.cam.style.width = data.width or 100
+        data.cam.style.height = data.height or 100
+    else return end
+    if not Server or not Server._thread then
+        if not Gui._global().cams then
+            Gui._global().cams = {}
+            Gui._global().cam_index = 1
+        end
+        if data.cam then
+            local surface = data.surface and data.surface.index or nil
+            table.insert(Gui._global().cams,{cam=data.cam,entity=data.entity,surface=surface})
+        end
+    else
+        local thread = _thread()
+        local surface = data.surface and data.surface.index or nil
+        table.insert(thread.data.cams,{cam=data.cam,entity=data.entity,surface=surface})
+    end
+    return data.cam
+end
+
 Event.register(defines.events.on_tick, function(event)
 	if (event.tick/(3600*game.speed)) % 15 == 0 then
 		Gui.left.update()
-	end
+    end
+    if Gui._global().cams and is_type(Gui._global().cams,'table') and #Gui._global().cams > 0 then
+        local _cam = Gui._global().cams[Gui._global().cam_index]
+        if not _cam then Gui._global().cam_index = 1 return end
+        if not _cam.cam.valid then table.remove(Gui._global().cams,Gui._global().cam_index)
+        elseif not _cam.entity.valid then table.remove(Gui._global().cams,Gui._global().cam_index)
+        else _cam.cam.position = _cam.entity.position if not _cam.surface then _cam.cam.surface_index = _cam.entity.surface.index end Gui._global().cam_index = Gui._global().cam_index+1
+        end
+    end
 end)
 
 return Gui