lvgl_widgets.tc

lvgl_widgets.tc — LVGL Phase 2 demo (requires firmware with USE_TINYC_LVGL)

Source on GitHub

// lvgl_widgets.tc — LVGL Phase 2 demo (requires firmware with USE_TINYC_LVGL)
//
// A slider drives a bar + a value label; a switch tints the background. Shows the
// Phase 2 value-widget API: slider/bar/switch, SetValue/GetValue/SetRange, IsChecked,
// and the VALUE_CHANGED event routed through the poll ring.
//
// LVGL 9.5 event codes: 0=ALL, 10=CLICKED, 11=RELEASED, 35=VALUE_CHANGED.
// LVGL aligns: 2=TOP_MID, 9=CENTER.  Style props: 120=RADIUS.

#define ALIGN_TOP_MID        2
#define ALIGN_CENTER         9
#define EV_VALUE_CHANGED     35
#define STYLE_RADIUS         120

int sld;        // slider
int bar;        // mirror bar
int vlabel;     // value text
int sw;         // switch

int main() {
    lvglInit();
    lvglSetBgColor(0, 0x101820);

    int title = lvglLabel(0);
    lvglSetText(title, "Phase 2: value widgets");
    lvglSetTextColor(title, 0xFFFFFF);
    lvglAlign(title, ALIGN_TOP_MID, 0, 10);

    sld = lvglSlider(0);
    lvglSetSize(sld, 240, 18);
    lvglSetRange(sld, 0, 100);
    lvglSetValue(sld, 30, 0);
    lvglAlign(sld, ALIGN_CENTER, 0, -40);
    lvglEventEnable(sld, EV_VALUE_CHANGED);

    bar = lvglBar(0);
    lvglSetSize(bar, 240, 18);
    lvglSetRange(bar, 0, 100);
    lvglSetValue(bar, 30, 0);
    lvglSetStyleInt(bar, STYLE_RADIUS, 9);     // rounded bar
    lvglAlign(bar, ALIGN_CENTER, 0, 0);

    vlabel = lvglLabel(0);
    lvglSetText(vlabel, "30");
    lvglSetTextColor(vlabel, 0x40c0ff);
    lvglAlign(vlabel, ALIGN_CENTER, 0, 45);

    sw = lvglSwitch(0);
    lvglAlign(sw, ALIGN_CENTER, 0, 95);
    lvglEventEnable(sw, EV_VALUE_CHANGED);

    char buf[16];
    while (1) {
        while (lvglEvent()) {
            int o = lvglEventObj();
            if (o == sld) {
                int v = lvglGetValue(sld);
                lvglSetValue(bar, v, 1);            // mirror slider -> bar (animated)
                sprintf(buf, "%d", v);
                lvglSetText(vlabel, buf);
            } else if (o == sw) {
                if (lvglIsChecked(sw)) { lvglSetBgColor(0, 0x0a3a1a); }   // green when ON
                else { lvglSetBgColor(0, 0x101820); }
            }
        }
        delay(30);
    }
    return 0;
}