DVX_GUI/dvx/widgets/widgetSlider.c

// widgetSlider.c — Slider (trackbar) widget

#include "widgetInternal.h"


// ============================================================
// wgtSlider
// ============================================================

WidgetT *wgtSlider(WidgetT *parent, int32_t minVal, int32_t maxVal) {
    WidgetT *w = widgetAlloc(parent, WidgetSliderE);

    if (w) {
        w->as.slider.value    = minVal;
        w->as.slider.minValue = minVal;
        w->as.slider.maxValue = maxVal;
        w->as.slider.vertical = false;
        w->weight = 100;
    }

    return w;
}


// ============================================================
// wgtSliderGetValue
// ============================================================

int32_t wgtSliderGetValue(const WidgetT *w) {
    if (!w || w->type != WidgetSliderE) {
        return 0;
    }

    return w->as.slider.value;
}


// ============================================================
// wgtSliderSetValue
// ============================================================

void wgtSliderSetValue(WidgetT *w, int32_t value) {
    if (!w || w->type != WidgetSliderE) {
        return;
    }

    if (value < w->as.slider.minValue) {
        value = w->as.slider.minValue;
    }

    if (value > w->as.slider.maxValue) {
        value = w->as.slider.maxValue;
    }

    w->as.slider.value = value;
}


// ============================================================
// widgetSliderCalcMinSize
// ============================================================

void widgetSliderCalcMinSize(WidgetT *w, const BitmapFontT *font) {
    (void)font;

    if (w->as.slider.vertical) {
        w->calcMinW = SLIDER_THUMB_W + 4;
        w->calcMinH = SLIDER_THUMB_W * 5;
    } else {
        w->calcMinW = SLIDER_THUMB_W * 5;
        w->calcMinH = SLIDER_THUMB_W + 4;
    }
}


// ============================================================
// widgetSliderOnMouse
// ============================================================

void widgetSliderOnMouse(WidgetT *hit, int32_t vx, int32_t vy) {
    int32_t range = hit->as.slider.maxValue - hit->as.slider.minValue;

    if (range <= 0) {
        return;
    }

    int32_t thumbRange;
    int32_t thumbPos;
    int32_t mousePos;

    if (hit->as.slider.vertical) {
        thumbRange = hit->h - SLIDER_THUMB_W;
        thumbPos   = ((hit->as.slider.value - hit->as.slider.minValue) * thumbRange) / range;
        mousePos   = vy - hit->y;

        if (mousePos >= thumbPos && mousePos < thumbPos + SLIDER_THUMB_W) {
            // Click on thumb — start drag
            sDragSlider = hit;
            sDragOffset = mousePos - thumbPos;
        } else {
            // Click on track — jump to position
            int32_t newVal = hit->as.slider.minValue + ((mousePos - SLIDER_THUMB_W / 2) * range) / thumbRange;

            if (newVal < hit->as.slider.minValue) { newVal = hit->as.slider.minValue; }
            if (newVal > hit->as.slider.maxValue) { newVal = hit->as.slider.maxValue; }

            hit->as.slider.value = newVal;

            if (hit->onChange) {
                hit->onChange(hit);
            }
        }
    } else {
        thumbRange = hit->w - SLIDER_THUMB_W;
        thumbPos   = ((hit->as.slider.value - hit->as.slider.minValue) * thumbRange) / range;
        mousePos   = vx - hit->x;

        if (mousePos >= thumbPos && mousePos < thumbPos + SLIDER_THUMB_W) {
            // Click on thumb — start drag
            sDragSlider = hit;
            sDragOffset = mousePos - thumbPos;
        } else {
            // Click on track — jump to position
            int32_t newVal = hit->as.slider.minValue + ((mousePos - SLIDER_THUMB_W / 2) * range) / thumbRange;

            if (newVal < hit->as.slider.minValue) { newVal = hit->as.slider.minValue; }
            if (newVal > hit->as.slider.maxValue) { newVal = hit->as.slider.maxValue; }

            hit->as.slider.value = newVal;

            if (hit->onChange) {
                hit->onChange(hit);
            }
        }
    }
}


// ============================================================
// widgetSliderPaint
// ============================================================

void widgetSliderPaint(WidgetT *w, DisplayT *d, const BlitOpsT *ops, const BitmapFontT *font, const ColorSchemeT *colors) {
    (void)font;
    uint32_t fg = w->fgColor ? w->fgColor : colors->contentFg;

    int32_t range = w->as.slider.maxValue - w->as.slider.minValue;

    if (range <= 0) {
        range = 1;
    }

    if (w->as.slider.vertical) {
        // Track groove
        int32_t trackX = w->x + (w->w - SLIDER_TRACK_H) / 2;
        BevelStyleT groove;
        groove.highlight = colors->windowShadow;
        groove.shadow    = colors->windowHighlight;
        groove.face      = colors->scrollbarTrough;
        groove.width     = 1;
        drawBevel(d, ops, trackX, w->y, SLIDER_TRACK_H, w->h, &groove);

        // Thumb
        int32_t thumbRange = w->h - SLIDER_THUMB_W;
        int32_t thumbY     = w->y + ((w->as.slider.value - w->as.slider.minValue) * thumbRange) / range;

        BevelStyleT thumb;
        thumb.highlight = colors->windowHighlight;
        thumb.shadow    = colors->windowShadow;
        thumb.face      = colors->buttonFace;
        thumb.width     = 2;
        drawBevel(d, ops, w->x, thumbY, w->w, SLIDER_THUMB_W, &thumb);

        // Center tick on thumb
        drawHLine(d, ops, w->x + 3, thumbY + SLIDER_THUMB_W / 2, w->w - 6, fg);
    } else {
        // Track groove
        int32_t trackY = w->y + (w->h - SLIDER_TRACK_H) / 2;
        BevelStyleT groove;
        groove.highlight = colors->windowShadow;
        groove.shadow    = colors->windowHighlight;
        groove.face      = colors->scrollbarTrough;
        groove.width     = 1;
        drawBevel(d, ops, w->x, trackY, w->w, SLIDER_TRACK_H, &groove);

        // Thumb
        int32_t thumbRange = w->w - SLIDER_THUMB_W;
        int32_t thumbX     = w->x + ((w->as.slider.value - w->as.slider.minValue) * thumbRange) / range;

        BevelStyleT thumb;
        thumb.highlight = colors->windowHighlight;
        thumb.shadow    = colors->windowShadow;
        thumb.face      = colors->buttonFace;
        thumb.width     = 2;
        drawBevel(d, ops, thumbX, w->y, SLIDER_THUMB_W, w->h, &thumb);

        // Center tick on thumb
        drawVLine(d, ops, thumbX + SLIDER_THUMB_W / 2, w->y + 3, w->h - 6, fg);
    }
}