Button

Buttons are a fundamental GUI element that provides a clickable area with an associated action. They are commonly used in dialogs and serve as a convenient way for users to interact with the touchscreen. Below is a simplified documentation for the GUIButton class.

Need code ?

You can jump right to the 👨‍💻 Usage or can refer to its original SDK Code if you need more details.

Constructor

GUIButton(
    uint16_t leftX, uint16_t topY, uint16_t rightX, uint16_t bottomY,
    const char *text,
    uint16_t eventID
)

Creates a basic button with the specified dimensions and text.

• leftX: x-coordinate of the left side of the button.
• topY: y-coordinate of the top side of the button.
• rightX: x-coordinate of the right side of the button.
• bottomY: y-coordinate of the bottom side of the button.
• text: text displayed on the button, indicating the action it performs.
• eventID: A unique identifier associated with the button, typically used to handle button clicks.

Optional “flags”

GUIButton(
    uint16_t leftX, uint16_t topY, uint16_t rightX, uint16_t bottomY,
    const char *text,
    uint16_t eventID, int flags
)

Creates a basic button with the flag capacity. For now, the only flag known is the “FlagEnabled” and could be found on the GUIButton.Flag enum.

Usage

Let’s create a button that says “Click Me !” :

// parent is the dialog or parent container

// the BUTTON_CLICK_EVENT_ID on click
const uint16_t BUTTON_CLICK_EVENT_ID = 1;

GUIButton m_buttonOK = new GUIButton(
    parent.GetLeftX() + 10,
    parent.GetTopY() + 40,
    parent.GetLeftX() + 10 + 95, // width of 95
    parent.GetTopY() + 40 + 30  //  height of 30
    "Click Me !",
    BUTTON_CLICK_EVENT_ID
);

// ...

// On the parent.OnEvent, here a GUIDialog :
virtual int OnEvent(struct GUIDialog_Wrapped *dialog, struct GUIDialog_OnEvent_Data *event) {
    if (event->GetEventID() == BUTTON_CLICK_EVENT_ID) {
        // TODO: do some action
        return 0;
    }
    // If we don't process the event, let the base class process it.
    return GUIDialog::OnEvent(dialog, event);
}

Use in C++ dialog

Need code ?

You can take a look at the 👨‍💻 demo gui for a complete example

// ...

class ButtonDialog : public GUIDialog {
public:
  ButtonDialog()
      : GUIDialog(Height35, AlignCenter, "Button Dialog", KeyboardStateNone),
        m_myBtn(GetLeftX() + 10, GetTopY() + 55, GetRightX() - 10,
                   GetTopY() + 85, "Button Text", BUTTON_MY_EVENT_ID) {
    AddElement(m_myBtn);
  }

  virtual int OnEvent(struct GUIDialog_Wrapped *dialog, struct GUIDialog_OnEvent_Data *event) {
    if (event->GetEventID() == BUTTON_CLICK_EVENT_ID) {
        // TODO: do some action
        return 0;
    }
    // If we don't process the event, let the base class process it.
    return GUIDialog::OnEvent(dialog, event);
  }

private:
  // use a custom event id here or just the GUIDialog::DialogResult*
  static const int BUTTON_MY_EVENT_ID = 1;

  GUIButton m_myBtn;
};