FireMonkey – iOS styles (problems and solutions)

In this post we’ll discover and solve a couple of glitches in the default styles supplied in FireMonkey for iOS.

  • Create a new FireMonkey iOS HD application.
  • Drop a button on the form and assign an OnClick handler.
  • In the OnClick handler, add code to display a simple message.
    • i.e. ShowMessage(‘You tapped me!’);
  • Run the application (you can do this on windows without going to XCode for this post)
  • Tap/Click on the button

Problem 1 – The default TButton style doesn’t look different when it has been pressed.

To fix this issue stopped the application and perform the following steps.

Right click on the TButton component and select the Edit Default Style… command at the bottom of the context menu.

The Style Designer will load and since we are updating the Default Style, will have the default style name for TButton, which is Buttonstyle.

The style consists of a TLayout, three TRectangle and a TText control.

To rectify the pressed state, grab a TInnerGlowEffect component from the Tool Palette.

Drag the TInnerGlowEffect component from the Tool Palette and drop it on the background TRectangle control.

With the TInnerGlowEffect component selected, you can see the available properties for the control.

Change the GlowColor property to better suit this situation, I chose Black.
Set the Enabled property to False. This is because we only want this effect enabled when the button is being pressed.
In the Trigger property, enter the following “IsPressed=true“. This means then whenever the IsPressed property is true, this effect will become enabled.

After your changes, you object inspector should look like the capture below.

Run the application now and hopefully you will see the effect display when the button is pressed.

Drop a couple of TCornerButton controls on the same application. Set the XRadius and YRadius values to 10 for one of the corner buttons. The sample application should now look something like the capture below.

Problem 2 – Under side of corner button looks strange when XRadius and YRadius values are not 3.

Below is a close up to better display the issue, it is really noticeable if your background is lighter.

To discover what is occuring with this style issue, we need to inspect the source code. Most importantly where the style information is loaded by the corner button control. In FireMonkey style properties should be modified in the ApplyStyle or ApplyStyleLookup methods. The ApplyStyle method for the TCustomCornerButton control is below, seems like everything should work.

Lets take a look at the default style for a TCornerButton.

Hmm, the source code referenced a StyleName called ‘secondbackground‘ button second background has been been set. The TRectangle without a name next to it should be called ‘secondbackground‘.

Use the object inspector to set the StyleName of the un-style-named TRectangle to ‘secondbackground‘.

Successful renaming is identified by your style, looking like the style in the capture below. Don’t set the name property by accident. You can’t set the name property to anything for a style (and have it persist).

Now when you view the form the corner button style won’t looked odd.

Problem 3 – The cornerbutton doesn’t show any effect when it is pressed.

Note how there is no TInnerGlowEffect define for the style. Follow the same steps above for the TButton and add the same effect (with the same property values) to the corner button style. Parent the TInnerGlowEffect to the background TRectangle control.

Problem 4 – The corner button has a TGlowEffect.

Kind of useless in a mobile application which doesn’t have a tab key to navigate between controls! Delete the TGlowEffect component from the style by clicking on the X.

Now you can rebuild and deploy to XCode and run on iOS to make sure these changes work well. Here is a capture from a real iPad (really it is!).

Default Styles

When in the Style Designer you can use the Load Default button to load all of the style details for the applications default style. This allows you to inspect other styles to learn from them. After making changes, I recommend you save the modified style to disk for safe keeping.

I would attach the modified style file to this post for download, but I’m not sure if I’m allowed to.

 

I’ve been doing a quite a bit of work with FireMonkey styles lately trying to make a nice TListBoxItem style. You may hear more about this in the future…

 

 

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