catching a button_click as variable/string

MDEnt · Mar 13, 2011

If I were to have a number of buttons spread throughout my app - across different panels for example. Is there an easy way to catch the button name that was clicked as a variable/string?

Thanks to all for a great support on a great product.

JogiDroid · Mar 13, 2011

MDEnt said:
If I were to have a number of buttons spread throughout my app - across different panels for example. Is there an easy way to catch the button name that was clicked as a variable/string?

Thanks to all for a great support on a great product.

You could use buttons Tag property/variable to hold your object/string..

MDEnt · Mar 14, 2011

OK, I could probably use the Tag in my project.

If I were to plan on using an IF to detect the click of a button, how do I detect/capture the tag for which button has been clicked?

Thanks for the help.

kickaha · Mar 14, 2011

In a Click event, the value 'Sender' is a pointer to the object that raised the Click event. So if you want the Tag value stored in GetTagValue, use this code in the Click event:

B4X:

   Dim btn As Button
   btn = Sender
   GetTagValue=btn.Tag

FrankR · Mar 14, 2011

But why no Name/Id attribute

I came across this over the weekend myself, and I'm using Tag for now.

But why don't we have a Name/id attribute?

kickaha · Mar 14, 2011

FrankR said:
I came across this over the weekend myself, and I'm using Tag for now.

But why don't we have a Name/id attribute?

Some reading for you

FrankR · Mar 14, 2011

Thank you for pointing out that previous dialog.

Still not following why we wouldn't have a separate name attribute.
Even if it is not precisely the java i.d. under the covers, I don't know why
we wouldn't have a separate tag element called Name that we can use the same way we're using Tag for finding Views, saving Tag for other uses.

FrankR · Mar 14, 2011

Also, is everyone doing like me and iterating through all the controls of a parent to find a particular control, or is there some simpler approach I'm not aware of yet?

agraham · Mar 14, 2011

You could stick them in a Map and get them that way. It would be far more efficient.

B4X:

Dim Map1 As Map
Map1.Initialize
...
Dim b As Button
name = "aname"
b.Initialise(name)
Map1.Put(name, b) ' key can be whatever you want
...
Dim b2 As Button
b2 = Map1.Get("name")

kickaha · Mar 14, 2011

agraham said:
You could stick them in a Map and get them that way. It would be far more efficient.

B4X:

Dim Map1 As Map Map1.Initialize ... Dim b As Button name = "aname" b.Initialise(name) Map1.Put(name, b) ' key can be whatever you want ... Dim b2 As Button b2 = Map1.Get("name")

TOP TIP :sign0098:, I will be using that some time soon.

MDEnt · Mar 14, 2011

A few interesting options it seems - utlimately here is what I am trying to accomplish:

I have 25 buttons (each one on a separate page/view in designer) - each button is named similar (buttonV1, buttonV2 ... etc.)

I have 25 Subs each very much identical - the button simply moves to the next panel...

Sub buttonV1_Click
Load PageV2
End Sub

Sub buttonV2_Click
Load PageV3
End Sub

and so on...

everything works fine as it is - my number of panels with buttons may grow - so I'm looking to (efficiently) consolidate all the subs into a single sub by somehow making a single variable that can identify which button was clicked and pass the variable to the sub by building a string for example - that way it will call the appropriate next panel in the series.

kickaha · Mar 14, 2011

MDEnt said:
A few interesting options it seems - utlimately here is what I am trying to accomplish:

I have 25 buttons (each one on a separate page/view in designer) - each button is named similar (buttonV1, buttonV2 ... etc.)

I have 25 Subs each very much identical - the button simply moves to the next panel...

Sub buttonV1_Click
Load PageV2
End Sub

Sub buttonV2_Click
Load PageV3
End Sub

and so on...

everything works fine as it is - my number of panels with buttons may grow - so I'm looking to (efficiently) consolidate all the subs into a single sub by somehow making a single variable that can identify which button was clicked and pass the variable to the sub by building a string for example - that way it will call the appropriate next panel in the series.

What you need to do is to set the event name of all the buttons to be the same (eg HandleButtons), and the tag to be the individual panel name
Then in the HandleButtons_Click event:

B4X:

Dim btn As Button
btn = Sender
GetTagValue=btn.Tag
Load GetTagValue

MDEnt · Mar 14, 2011

Yes, I see how this could work. I'm playing around with it as suggested and getting:

Compiling code. Error
Error parsing program.
Error description: Undeclared variable 'load' is used before it was assigned any value.
Occurred on line: 130
Load GetTagValue

agraham · Mar 14, 2011

MDEnt said:
Load GetTagValue

That is not valid B4A syntax. Assuming you have writen a Sub called Load

Sub Load(page As String)
...
End Sub

Then you need to call it as

Sub button_Click
Dim btn As Button
btn = Sender
GetTagValue=btn.Tag
Load(GetTagValue)
End Sub

kickaha · Mar 14, 2011

MDEnt said:
Yes, I see how this could work. I'm playing around with it as suggested and getting:

Compiling code. Error
Error parsing program.
Error description: Undeclared variable 'load' is used before it was assigned any value.
Occurred on line: 130
Load GetTagValue

Sorry, I was assuming that your code example

B4X:

Sub buttonV2_Click
Load PageV3
End Sub

was paraphrased, and worded mine accordingly.

If you post up how you want the panels handling (are you creating them "on the fly" or just showing/hiding them) then we can probably advise (post one of the actual subs you have at the moment).

MDEnt · Mar 14, 2011

Frst off - thanks so much to all for the help - learning a lot here with all suggestions.

Actually my provided code example is correct (my bad with having a space after the Load in my initial example) in that it calls the panel in a further sub (for other programmatic reasons) example follows:

Sub buttonV2_Click
LoadPageV3
End Sub
.
.
.
Sub LoadPageV3
panel03.Initialize("panel03")
Activity.AddView(panel03, 0, 0, 100%x, 100%y)
panel03.LoadLayout("page03")
End Sub
.
.
.
Sub buttonV3_Click
LoadPageV4
End Sub
.
.
.
Sub LoadPageV4
panel04.Initialize("panel04")
Activity.AddView(panel04, 0, 0, 100%x, 100%y)
panel04.LoadLayout("page04")
End Sub
.
.
.
etc.

Right now I'm trying to consolidate all the buttonVX_clicks into one sub - then I'll tackle consolidating the panel subs down the road...

kickaha · Mar 14, 2011

OK, try this:
set the event name of all the buttons to be the same (eg HandleButtons)
set the tag to be the individual sub name (LoadPageV3 etc)

Then in the HandleButtons_Click event:

B4X:

Dim btn As Button
btn = Sender
GetTagValue=btn.Tag
CallSub("",GetTagValue)

You can probably do away with using a string for GetTagValue -
try CallSub("",btn.Tag)

MDEnt · Mar 14, 2011

Success! Thanks so much!

Now to consolidate those panel subs - a new question thread coming soon I'm sure!

kickaha · Mar 15, 2011

MDEnt said:
Success! Thanks so much!

Now to consolidate those panel subs - a new question thread coming soon I'm sure!

Store your Panels in a list and reference them by number?

CarlM · Apr 26, 2012

kickaha said:
OK, try this:
set the event name of all the buttons to be the same (eg HandleButtons)

:sign0013:

Sorry to hijack this - but I can't find how to set an event handler to a sub that I created in code (eg: Sub FireWhenAnyButtonIsClicked). Using the designers 'Generate Members' creates a sub for each control/view; but its not possible to generate a single Sub for multiple views using this option.

Do I need to create the buttons in code then inititialise them with the same argument?

Thanks.

Sorry - I have it - - using Search and tutorials helps!

catching a button_click as variable/string

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