Mixing sub-menus and scrolling lines?

[fred-76]

Hello

I'm very confused with the syntax of this library. It seems there is a logic, but I can't figure it out...

Is it possible to have such structure on a 2 lines LCD, for example:

Main Menu:

• Equipment
• Parameters
• Go

Sub menu Equipment:

• Focal length:...
• Aperture:...
• Exposure:...

Sub menu Parameters:

• LCD Brightn:...
• LCD Contrast:...
• Delay:...

Sub menu Go:

• Confirm
• Cancel

It is about a day I try and I can't make it work...

Whether I use your example with system menu and I can only do 2 lines submenus, whether I use your example with scrolling menus but I can't do submenus. I really don't undestand how to mix them... Do you have a step by step tutorial (or a link to) ?

All the best

Fred

[VasilKalchev]

Hello @fred-76.

To achieve this menu structure, you need to put every LiquidScreen in its own LiquidMenu, since you're navigating the menu hierarchically (not scrolling through the screens). Here is an example:

// lName - LiquidLine object
// sName - LiquidScreen object
// mName - LiquidMenu object
// fName - callback function

uint16_t var = 123;

LiquidLine lEquipment(0, 0, "Equipment");
LiquidLine lParameters(0, 0, "Parameters");
LiquidLine lGo(0, 0, "Go");
LiquidScreen sMain(lEquipment, lParameters, lGo);
LiquidMenu mMain(lcd, sMain);

LiquidLine lFocal(0, 0, "Focal length: ", var);
LiquidLine lAperture(0, 0, "Aperture: ", var);
LiquidLine lExposure(0, 0, "Exposure: ", var);
LiquidScreen sEquipment(lFocal, lAperture, lExposure);
LiquidMenu mEquipment(lcd, sEquipment);

LiquidLine lLcdBrightness(0, 0, "LCD brightness: ", var);
LiquidLine lLcdContrast(0, 0, "LCD contrast: ", var);
LiquidLine lDelay(0, 0, "Delay: ", var);
LiquidScreen sParameters(lLcdBrightness, lLcdContrast, lDelay);
LiquidMenu mParameters(lcd, sParameters);

LiquidLine lConfirm(0, 0, "Confirm");
LiquidLine lCancel(0, 0, "Cancel");
LiquidScreen sGo(lConfirm, lCancel);
LiquidMenu mGo(lcd, sGo);

LiquidSystem liquidSystem(mMain, mEquipment, mParameters, mGo);

// Used for attaching something to the lines, to make them focusable.
void fBlankFunction() {
    return;
}

void fConfirm() {
  return;
}
void fCancel() {
  return;
}

void goto_mEquipment() {
  liquidSystem.change_menu(mEquipment);
}
void goto_mParameters() {
  liquidSystem.change_menu(mParameters);
}
void goto_mGo() {
  liquidSystem.change_menu(mGo);
}
void goto_mMain() { // you can call this directly from a designated "back" button
  liquidSystem.change_menu(mMain);
}


void setup() {
    Serial.begin(250000);

    lcd.begin(16, 2);

    // Attaching a function to the lines is required for scrolling to work.
    lEquipment.attach_function(1, goto_mEquipment);
    lParameters.attach_function(1, goto_mParameters);
    lGo.attach_function(1, goto_mGo);
    
    lFocal.attach_function(1, fBlankFunction);
    lAperture.attach_function(1, fBlankFunction);
    lExposure.attach_function(1, fBlankFunction);
    
    lLcdBrightness.attach_function(1, fBlankFunction);
    lLcdContrast.attach_function(1, fBlankFunction);
    lDelay.attach_function(1, fBlankFunction);

    lConfirm.attach_function(1, fConfirm);
    lCancel.attach_function(1, fCancel);
    
    // Set the number of lines the display has.
    /*
     * Setting this is a must when you want to add more "lines" than
     * the display actually has (the extra lines will be scrolled).
     * This must be set after adding the "lines" to the "screen".
     */
    sMain.set_displayLineCount(2);
    sEquipment.set_displayLineCount(2);
    sParameters.set_displayLineCount(2);
    sGo.set_displayLineCount(2);

    liquidSystem.update();
}

One caveat when using scrollable screens is that every LiquidLine that can go off-screen must have some function attached to it (even if it is blank), This is just the way that scrolling works. But I don't think you'll have this problem judging by your example.