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dev42
Level 7

fake Modal Menu with getMessagePort()

In trying to roll my own Modal pop-up menu, I quickly ( it's all relative! )
learned that I can't have a Modal anything! My app needs to keep doing
stuff even when menus and such are on screen awaiting user input.

So, in using getMessagePort() to hijack my main event loop, it crossed my
mind that I could send other "doEvent()/Update()" functions as parameters
into my Fake-Modal Menu of Awesomeness.

Q: As much as the possibility of this working is intriguing, how often is
such a construct put into action? Is this a standard way of doing such
a thing? If not, why have a getMessagePort() at all?

Follow-up Q: Are easing animations typically modal as well? Who here has
implemented non-modal transition animations?

Thanks in advance.

peace & 42
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14 Replies
Rek
Level 7

Re: fake Modal Menu with getMessagePort()

"dev42" wrote:
In trying to roll my own Modal pop-up menu, I quickly ( it's all relative! )
learned that I can't have a Modal anything! My app needs to keep doing
stuff even when menus and such are on screen awaiting user input.

So, in using getMessagePort() to hijack my main event loop, it crossed my
mind that I could send other "doEvent()/Update()" functions as parameters
into my Fake-Modal Menu of Awesomeness.

Q: As much as the possibility of this working is intriguing, how often is
such a construct put into action? Is this a standard way of doing such
a thing? If not, why have a getMessagePort() at all?

Follow-up Q: Are easing animations typically modal as well? Who here has
implemented non-modal transition animations?

Thanks in advance.

peace & 42


Are you using the 2D api for this?
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dev42
Level 7

Re: fake Modal Menu with getMessagePort()

"Rek" wrote:
Are you using the 2D api for this?

Yes.
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NewManLiving
Level 7

Re: fake Modal Menu with getMessagePort()

just pass control to a message loop in your modal dialog. Use getmessage instead of wait or waitmessage
My Channels: 2D API Framework Presentation: https://owner.roku.com/add/2M9LCVC
Updated: 11-11-2015 - Completed Keyboard interface
The Joel Channel ( Final Beta )
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dev42
Level 7

Re: fake Modal Menu with getMessagePort()

"NewManLiving" wrote:
just pass control to a message loop in your modal dialog. Use getmessage instead of wait or waitmessage

could you expound on this a bit? What exactly do you mean by "pass control"? Smiley Surprisedops: :?:
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NewManLiving
Level 7

Re: fake Modal Menu with getMessagePort()

When you create your dialog you first draw it and then go into another message loop. But you do not use wait. Instead you use getmessage which returns immediately if there's no button pressed. it just returns invalid. So if you have to keep processing something you can continue until you notice some valid input. Of course what you are doing should not block the message queue either. If You have to block the queue then you don't even need a loop. What is it that you are trying to do?
My Channels: 2D API Framework Presentation: https://owner.roku.com/add/2M9LCVC
Updated: 11-11-2015 - Completed Keyboard interface
The Joel Channel ( Final Beta )
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dev42
Level 7

Re: fake Modal Menu with getMessagePort()

"NewManLiving" wrote:
What is it that you are trying to do?

Code better? Smiley Wink That really isn't a joke! I've apparently coded myself into a corner. I've been working on a game loop "framework" that I could use in the future and not just on the app I'm currently working on. One "feature" of this framework was that I allowed more than one object to process button events. Not only that, but some objects, depending on which button was pressed, could pass which button was pressed on to the next object in the list... or not.

To facilitate all of this, I started accumulating a bunch of boolean flags: .isVisible, .hasFocus, .isModal

Now I'm not saying I was completely wrong ( why would any programmer *ever* say that?! ), but I'm starting to see that I really was over-complicating things.

"NewManLiving" wrote:
another message loop

That's just it. I only had one loop. This is new territory for me. I'm currently working through the 7 Stages of Learning to Program Better ( aka Programming Grief ). I initially posted when at the first stage, Shock & Denial. I won't go into the other stages as I don't want to cause anybody undue stress revisiting their past programming learning journeys. Smiley Wink

"NewManLiving" wrote:
What is it that you are trying to do?

Topically? errr to learn if implementing more than one event loop is the way to go.
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Rek
Level 7

Re: fake Modal Menu with getMessagePort()

"dev42" wrote:
"NewManLiving" wrote:
What is it that you are trying to do?

Code better? Smiley Wink That really isn't a joke! I've apparently coded myself into a corner. I've been working on a game loop "framework" that I could use in the future and not just on the app I'm currently working on. One "feature" of this framework was that I allowed more than one object to process button events. Not only that, but some objects, depending on which button was pressed, could pass which button was pressed on to the next object in the list... or not.

To facilitate all of this, I started accumulating a bunch of boolean flags: .isVisible, .hasFocus, .isModal

Now I'm not saying I was completely wrong ( why would any programmer *ever* say that?! ), but I'm starting to see that I really was over-complicating things.

"NewManLiving" wrote:
another message loop

That's just it. I only had one loop. This is new territory for me. I'm currently working through the 7 Stages of Learning to Program Better ( aka Programming Grief ). I initially posted when at the first stage, Shock & Denial. I won't go into the other stages as I don't want to cause anybody undue stress revisiting their past programming learning journeys. Smiley Wink

"NewManLiving" wrote:
What is it that you are trying to do?

Topically? errr to learn if implementing more than one event loop is the way to go.


We only use 1 run-loop in our app. The key is to arrange components in a hierarchy and allow them to register with their parents as event receivers. Whenever an event is pulled out of the message port in the main loop, send it to the root component. Each component then either handles the event, or forwards it to it's children, who can also handle, or forward it. Here's some pseudo code:

**Disclaimer** This was all typed directly into the forum... It might not compile/run, but should demonstrate the concept

' -----------------------------------------------
' Entry: Main
function main() as Void
runloop = runloopCreate()

' Create a button
button = buttonCreate()
button.setText("Click Me!") ' setText not included in example

' Add button
runloop.getRoot().addChild(button)

' Execute
runloop.run()
end function

' -----------------------------------------------
' Class: Component

function componentCreate() as Object
return {
handleEvent : _component_handleEvent
handleOrForwardEvent: _component_handleOrForwardEvent

_children : []
addChild : function(component as Object) as Object: m._children.push(component): end function
}
end function

function _component_handleOrForwardEvent(event as Object) as Boolean
handled = m.handleEvent(event)

' We did not handle the event, maybe our children will?
if not handled
for i = 0 to m._children.count() - 1
handled = m._children[i].handleOrForwardEvent(event)
if handled then exit for
end for
end if

return handled
end function

function _component_handleEvent(event as Object) as Boolean
return false ' No handling of events at this level
end function

' -----------------------------------------------
' Class: Button

function buttonCreate() as Object
this = componentCreate()

' Override function handleEvent
this.handleEvent = _button_handleEvent
this.performClick = _button_performClick
return this
end function

function _button_handleEvent(event as Object) as Boolean
buttonCodes = bslUniversalControlCodes()
if event.getInt() = buttonCodes.button_select_pressed
m.performOnClick()
return true ' We handled this event
end if

return false ' We didn't handle this event -- it should be passed to others who may wish to handle it
end function

function _button_performClick() as Void
?"Button was clicked!"
end function

' -----------------------------------------------------------------------------
' Run Loop

function runloopCreate() as Object
return {
_exited : false
_root : componentCreate()
run : _runloop_run

getRoot: function() as Object: return m._root: end function
}
end function

function _runloop_run() as Void
while not m._exited
event = m._messagePort.getMessage()
if event <> invalid then m._root.handleOrForwardEvent(event)

' ... snip other run-loop stuff like drawing ...
end while
end function
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dev42
Level 7

Re: fake Modal Menu with getMessagePort()

TYVM ... for your time and code!

I need to go over your framework 42 more times, but I'm starting to see similarity in what I've done.
( Is it common to create a framework and then become fuzzy on how it works? Smiley Surprisedops: )

But that's part of the reason for the thread. I have a working menu that is non-modal, but it isn't quite the same as a roMessageDialog in look-n-feel. Thus the attempt to initially use and now attempt to roll my own. I am reconsidering this and wondering if it wouldn't be easier to try to spiffy up what I already have working, but due to some "genius" reasoning on my part, my_menu and my_textbox are tightly integrated. Saved time / code before, more discomfort today. Smiley Tongue

peace & 42
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Rek
Level 7

Re: fake Modal Menu with getMessagePort()

"dev42" wrote:
Is it common to create a framework and then become fuzzy on how it works? Smiley Surprisedops:


In short, yes. That's why separation of concerns and good documentation is critical to good architecture. If you have undocumented assumptions or dependencies, chances are in 8 months you'll forget about them.

"dev42" wrote:
Saved time / code before, more discomfort today. Smiley Tongue


Been there. Sounds like time for a refactor! Smiley Very Happy
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