This topic provides step-by-step instructions to design a simple UI for the LED indicator application. You need Qt Design Studio to get started. If you don't have it installed, install it using the Qt Online Installer or Maintenance Tool.

The following instructions guide you through the complete design process:

1. Create a new project:
   • Launch Qt Design Studio and click Create Project.

     

   • Select the Qt for MCUs tab in the New Project wizard.
   • Select 480 x 272 as the resolution.

     

   • Name your project and click Create.

     

   You should now see the Design Mode UI and the boilerplate project with a Rectangle and Text item.

   

2. Select the Rectangle either in the Navigator pane or Form Editor to change its properties in the Properties pane:
   • Change the Fill color property to black either by using the color picker or entering Hex code (#000000) manually.

     

3. Select the Text item either in the Navigator pane or Form Editor to change its properties:
   • Change Text Color to white either using the color picker or entering Hex code (#ffffff) manually.
   • Change Units to px and Size to 14.
   • Change Text to LED 1.

     

4. Add the button rectangle:
   • Find the Rectangle component in the Components pane under the Basic components. Drag it onto the Rectangle in the Navigator pane.

     

   • Select the new rectangle in the Navigator pane to change some of its properties in the Properties pane:
     • Change its Fill color property to grey by either using the color picker or entering the Hex code (#808080) manually.
     • Size to 120 W x 60 H.

       

     • Switch to the Layout section in the Properties pane. Anchor the rectangle to the center of its parent.

       

     • Drag the existing Text component onto the new Rectangle.

       

5. Assign unique ID to each item:
   • Name the Text item as buttonText.

     

   • Name the inner Rectangle item as buttonRectangle.
   • Name the parent Rectangle item as backgroundRectangle.
6. Add a MouseArea:
   • Find the MouseArea component in the Components pane under the Basic components. Drag it onto the inner Rectangle in the Navigator pane.

     

   • Double-click on the mouseArea component to name it as buttonMouseArea.
   • Anchor it to span its parent, buttonRectangle.

     

7. Bind the button's color property to the pressed property of MouseArea:
   • Select buttonRectangle in the Navigation pane.
   • Select Connection View from the View > Views menu.

     

   • Switch to the Bindings tab in the Connection View .
   • Click + to add a new binding.

     

   • Select color for the Property column and buttonMouseArea for the Source Item column of the new binding.
   • Right-click on the new binding to select Open Binding Editor from the context menu.
   • Add the following expression in the editor and click OK:

     buttonMouseArea.pressed ?
         UICommunicator.led1Status ? "blue" : "grey" :
         UICommunicator.led1Status ? "darkblue" : "dimgrey"

   Note: UICommunicator is the C++ backend that you add in the next topic.

   

8. Add a connection for the onClicked handler of MouseArea:
   • Select buttonMouseArea in the Navigation pane.
   • Select the Connections tab in the Connection View pane.
   • Click + to add a new connection:

     

   • Right-click on the new connection and select Open Connection Editor from the context menu.
   • Add the following code in the editor and click OK:

     UICommunicator.sendFromUI(
         UICommunicator.LED1State,
         !UICommunicator.led1Status)

     

9. Save and close.
   • Select File > Save All to save your change.
   • Select File > Close Project <your-project-name> to close the project.