1. I have found the Global String: OPTION_TOOLTIP_SHOW_FULLSCREEN_STATUS

    That appears to be able to flash the red warning around the edges of the screen. I have no idea how to implement it to do so.

    I have an addon. It checks certain conditions when the player enters combat. If certain conditions are achieved, I want the addon to flash the screen with the red warning around the edges until an action is taken to change the conditions being monitored.

    How do I cause the screen to flash the red warning around the screen?

    You need to find that frame, and manipulate it. The global string has nothing to do with that.

    The frame would be the main UI. The Wow Window.

    I suppose I could create a full screen Message Frame in the background using: SetupFullscreenScale(Frame) Frame:SetBackdropColor(red, green, blue [, alpha]) Frame::SetFrameStrata("BACKGROUND") Frame:Hide();

    And then use: UIFrameFlash(frame, fadeInTime, fadeOutTime, flashDuration, showWhenDone, flashInHoldTime, flashOutHoldTime)

    To flash it. Does that sound reasonable?

    ... no. The frame that has the full screen flash. Or the textures that make up the flash, depending on how it's defined. Regardless, I don't know what your question really is.. I can't write the addon for you. You need to find the place that the full screen flash frame is defined in the FrameXML, and then show it.

    I was editing the previous response when you posted. I had an idea listed there.

    Not sure why you need a message frame to do that, if you're not going to be sending messages to it. Also, a backdrop at that scale is probably going to look pretty ridiculous, but it's a place to start. I'd suggesting using a 'Frame', no need to initialize another widget when it's not necessary. Then you should be able to flash it once you've got it all set up.

    The two textures used by WoW are:

    http://wowprogramming.com/utils/artbrowser/FullScreenTextures.list

    Better to use them than a backdrop, imo.

    Thank you, I'll check them out.

    To set those textures would I use "OutofControl", or will I need a path like "FullScreen Textures\\OutofControl.blp" ?

    "Interface\\FullScreen Textures\\OutofControl"

    I just added a texture to the Main XML frame of the addon, using:

    Texture

    name="AspectWarning"

    file="Interface\FullScreenTextures\OutOfControl"

    alphaMode="ADD"

    hidden="true"

    I finally did it with a script. This is the routine used. The control variables (Aspect.###) are from elsewhere in the addon.

    function AspectFlashScreen()

    if(not Aspect.StopFlash) then
        local r = 1;
        local g = 0;
        local b = 0;
        local a = .50;
        ASPECT_CurrentSound = ASPECT_HawkSound;
        if (Aspect.Current == "Viper") then
            r = 0;  
            b=1;
            a=.50;
            ASPECT_CurrentSound = ASPECT_HissSound;
        end
        if not flasher then
            flasher = CreateFrame("Frame", "AWFlash", UIParent)
            flasher:SetFrameStrata("BACKGROUND")
            flasher:SetBackdrop({bgFile = "Interface\\Tooltips\\UI-Tooltip-Background",})
            flasher:SetAllPoints(UIParent)
            flasher:SetScript("OnShow", function(self)
                self.elapsed = 0
                self:SetAlpha(0)
            end)
            flasher:SetScript("OnUpdate", function(self, elapsed)
                elapsed = self.elapsed + elapsed
                AspectFlasherSound();
                if (Aspect.StopFlash or UnitIsDead("player")) then
                    self:Hide()
                    self:SetAlpha(0)
                    flashcount = 0;
                    Printcount = true;
                    return
                end
                local alpha = elapsed % 0.4
                if elapsed > 0.2 then
                    alpha = 0.4 - alpha
                end
                self:SetAlpha(alpha * 5)
                self.elapsed = elapsed
            end)
            flasher:Hide()
        end
        if(Aspect.Flash) then
            flasher:SetBackdropColor(r, g, b, a)
            flasher:Show()
        end
    end
    

    end

    The textures you gave me would have worked better, but they are not transparent in "black" regions. If you could tell me how to use them instead of "Interface\Tooltips\UI-Tooltip-Background", and not have them black out the center of the screen, that would be helpful.

    You'd need to set the blend mode of the texture using SetBlendMode.

    I could simply change the bgfile to the OutofControl background, but then I am operating with a frame. SetBlendMode only works with textures. How would I maintain the functionality of this routine and adjust the blend mode of the frame?

            flashedge = CreateFrame("Frame", "AWFlash", UIParent)
            flashedge:SetFrameStrata("BACKGROUND")
            flashedge.texture = flashedge:CreateTexture();
            flashedge.texture:SetAllPoints(flashedge);
            flashedge.texture:SetTexture("Interface\\FullScreenTextures\\OutofControl");
            flashedge:SetBlendMode("ADD");
    

    I get this error:

    Interface\AddOns\Aspect\Aspect.lua:445: attempt to call method 'SetBlendMode' (a nil value) Count: 1

    As the documentation pretty clearly states, it's a method on a texture.. not a frame.

    Indeed it does. Final flasher frame that uses the blend method:

     function Aspect_CreateFlasher(color)
        local frameImage = "None";
        if(color == "Blue") then
            frameImage = "Interface\\FullScreenTextures\\OutofControl";
        elseif(color == "Red") then
            frameImage = "Interface\\FullScreenTextures\\LowHealth";
        else
            frameImage = nil;
        end
    
        local frameName = "Aspect"..color.."WarningFrame";
        if not ((Flasher[color]) and (frameImage)) then
            local flasher = CreateFrame("Frame", frameName)
            flasher:SetToplevel(true)
            flasher:SetFrameStrata("FULLSCREEN_DIALOG")
            flasher:SetAllPoints(UIParent)
            flasher:EnableMouse(false)
            flasher.texture = flasher:CreateTexture(nil, "BACKGROUND")
            flasher.texture:SetTexture(frameImage)
            flasher.texture:SetAllPoints(UIParent)
            flasher.texture:SetBlendMode("ADD")
            flasher:Hide()
            flasher:SetScript("OnShow", function(self)
                self.elapsed = 0
                self:SetAlpha(0)
            end)
            flasher:SetScript("OnUpdate", function(self, elapsed)
                elapsed = self.elapsed + elapsed
                if Aspect_FlasherSound(sound) then
                    self:Hide()
                    self:SetAlpha(0)
                    flashcount = 0;
                    Printcount = true;
                    Control.PrintAspect = "Dragonhawk";
                    return
                end
                local alpha = elapsed % 0.4
                if elapsed > 0.2 then
                    alpha = 0.4 - alpha
                end
                self:SetAlpha(alpha * 5)
                self.elapsed = elapsed
            end)
            Flasher[color] = flasher;
        end
     end
    

    Awesome, looks great!