Drawing to TFT Using Variables Not Hard Coding

Projects Programming
1

This is a preliminary question as I am yet to hit the keyboard and start coding but I want to write good code using good practices.

I will be having 2 pages on a TFT. The first will have maybe 10 buttons/text and the second will have a multiple column/rowed table of data. To setup the outline of the table I could obviously hard code the coordinates into the sketch but should I ever want to make changes I would have to go through the code line by line to ensure I change all values. Is it perhaps better to use either integers or maybe arrays to store these values then reference those integers/arrays in the tft.drawline commands?

To draw a single button it might be something like;

int btnRecord[] = {10, 10, 60, 60};

myGLCD.drawRoundRect (btnRecord[0], btnRecord[1], btnRecord[2], btnRecord[3]);

This example is obviously highly simplified but it should show my thoughts. The real sketch would have dozens of buttons and/or lines etc

Is this good practice?? Would there be a high memory overhead??

2

Generally you would set up constants such as the height of a standard button and the height of each row of buttons.

myGLCD.drawRoundRect(col*COL_WIDTH, row*ROW_HEIGHT, BUTTON_WIDTH, BUTTON_HEIGHT);

....or something like that. There's no memory overhead. The compiler will do as much of the maths as it can before it even sends the code to the Arduino.

Then you take the code above and put it into a function so you can make calls like...

drawButton(1,5,"Click Me");

Commonly-used items like the font color or button color should be given names too. Then you can adjust the exact shade of green that the 'active' buttons have and they all change together.