Radio Button
A Radio Button in TouchGFX is a widget that is aware of touch events and can send a callback when the Radio Button is clicked. A radio button consists of four images, corresponding to a selected or unselected button during a pressed or released state. Radio Buttons can be added to a Radio Button Group which handles the deselection of radio buttons when a new selection is made.
The Radio Button can be replicated with the Flex Button. A Flex Button is a more configurable button that takes up a bit more RAM in exchange for flexibility.
Radio Button running in the simulator
Widget Group
The Radio Button can be found in the Buttons widget group in TouchGFX Designer.
Radio Button in TouchGFX Designer
Properties
The properties for the Radio Button are described in the following sections.
| Property Group | Property Descriptions |
|---|---|
| Name | Name of the widget. Name is the unique identifier used in TouchGFX Designer and code. |
| Location | X and Y specify the top left corner of the widget relative to its parent. W and H specify the width and height of the widget. The size of a Radio Button is determined by the size of the selected images. Lock specifies if the widget should be locked in its current X, Y, W and H. Locking the widget also disables interacting with the widget through the screen. Visible specifies the visibility of the widget. Making the widget invisible also disables interacting with the widget through the screen. |
| Selection | Selected specifies the initial selection state of the button. Deselectable specifies the ability to deselect the button by pressing it while in the selected state. |
| Group | Group specifies the name of the group this button will be assigned to. Selection and deselection behaviour is contained within these Radio Button Groups. |
| Style | Style specifies a predefined setup of the widget, that sets select properties to predefined values. These styles contain images that are free to use. |
| Image | Released Image and Pressed Image specify the images assigned to the pressed and released states from the Designer skin library or the Project folder. |
| Appearance | Alpha specifies the transparency of the widget. The alpha value ranges between 0 and 255 for the widget. 0 is fully transparent and 255 is solid. |
| Mixins | Draggable specifies if the widget is draggable at runtime. ClickListener specifies if the widget emits a callback when clicked. FadeAnimator specifies if the widget can animate changes to its Alpha value. MoveAnimator specifies if the widget can animate changes to X and Y values. |
Interactions
The actions and triggers supported by the Radio Button are described in the following sections.
Actions
| Standard widget action | Description |
|---|---|
| Move widget | Move a widget to a new position over time. |
| Fade widget | Modify alpha value of widget over time. |
| Hide widget | Hides a widget (sets visibility to false). |
| Show widget | Make a hidden widget visible (sets visibility to true). |
Triggers
| Trigger | Description |
|---|---|
| Radio Button is selected | A Radio Button has been deselected. |
| Radio Button is deselected | A Radio Button has been selected. |
Performance
The Radio Button is composed of four images and is dependent on image drawing. Therefore, a Radio Button is considered a fast performing widget on most platforms.
For more details on image drawing performance, read the General UI Component Performance section.
Examples
Generated Code
In the generated code for the View base class we can see how TouchGFX Designer sets up a Radio Button.
Screen1ViewBase.cpp
#include <gui_generated/screen1_screen/Screen1ViewBase.hpp>
#include "BitmapDatabase.hpp"
creen1ViewBase::Screen1ViewBase() :
radioButtonSelectedCallback(this, &Screen1ViewBase::radioButtonSelectedCallbackHandler)
{
radioButtonName.setXY(136, 114);
radioButtonName.setBitmaps(touchgfx::Bitmap(BITMAP_BLUE_CHECK_BUTTONS_CHECK_MARK_INACTIVE_ID), touchgfx::Bitmap(BITMAP_BLUE_CHECK_BUTTONS_CHECK_MARK_PRESSED_ID), touchgfx::Bitmap(BITMAP_BLUE_CHECK_BUTTONS_CHECK_MARK_ACTIVE_ID), touchgfx::Bitmap(BITMAP_BLUE_CHECK_BUTTONS_CHECK_MARK_NORMAL_ID));
radioButtonName.setSelected(false);
radioButtonName.setDeselectionEnabled(true);
add(radioButtonName);
radioButtonGroupName.add(radioButtonName);
radioButtonGroupName.setRadioButtonSelectedHandler(radioButtonSelectedCallback);
}
void Screen1ViewBase::radioButtonSelectedCallbackHandler(const touchgfx::AbstractButton& src)
{
if (&src == &radioButtonName)
{
//InteractionName
//When buttonName clicked calls the new virtual function "functionName()" set by the user
functionName();
}
}
Tip
radioButtonName.invalidate() if you change the appearance of the widget.TouchGFX Designer Examples
To further explore the Radio Button, try creating a new application within TouchGFX Designer with the following UI template:
Radio Button Example UI template in TouchGFX Designer