DVX_GUI/widgets/widgetProgressBar.c

#define DVX_WIDGET_IMPL
// widgetProgressBar.c  -- ProgressBar widget
//
// A non-interactive fill-bar widget for displaying bounded progress.
// Supports both horizontal and vertical orientations via separate
// constructors rather than a runtime flag, because orientation is
// typically fixed at UI construction time and the two constructors
// read more clearly at the call site.
//
// Rendering: sunken 2px bevel border (inverted highlight/shadow to
// look recessed) with a solid fill rect proportional to value/maxValue.
// Uses integer division for fill size -- no floating point, which would
// be prohibitively expensive on a 486 without an FPU.
//
// The widget has no mouse or keyboard handlers -- it is purely display.
// Value is controlled externally through the set/get API.

#include "dvxWidgetPlugin.h"

static int32_t sTypeId = -1;

typedef struct {
    int32_t value;
    int32_t maxValue;
    bool    vertical;
} ProgressBarDataT;


// ============================================================
// widgetProgressBarCalcMinSize
// ============================================================

// Min size is based on font metrics to keep the bar proportional to
// surrounding text. The cross-axis uses charHeight+4 (room for the
// bar plus 2px bevel on each side). The main axis uses 12 char widths
// so the bar is wide enough to show meaningful progress granularity.
void widgetProgressBarCalcMinSize(WidgetT *w, const BitmapFontT *font) {
    ProgressBarDataT *d = (ProgressBarDataT *)w->data;

    if (d->vertical) {
        w->calcMinW = font->charHeight + 4;
        w->calcMinH = font->charWidth * 12;
    } else {
        w->calcMinW = font->charWidth * 12;
        w->calcMinH = font->charHeight + 4;
    }
}


// ============================================================
// widgetProgressBarPaint
// ============================================================

// Paint uses a two-pass approach: first the sunken bevel border, then
// the fill rect. The fill color defaults to activeTitleBg (the window
// title bar color) to provide strong visual contrast inside the
// recessed trough -- matching classic Win3.1/Motif progress bar style.
// When disabled, the fill becomes windowShadow to look grayed out.
//
// Vertical bars fill from bottom-up (natural "filling" metaphor),
// which requires computing the Y offset as (innerH - fillH).
void widgetProgressBarPaint(WidgetT *w, DisplayT *disp, const BlitOpsT *ops, const BitmapFontT *font, const ColorSchemeT *colors) {
    (void)font;
    ProgressBarDataT *d = (ProgressBarDataT *)w->data;
    uint32_t fg = w->enabled ? (w->fgColor ? w->fgColor : colors->activeTitleBg) : colors->windowShadow;
    uint32_t bg = w->bgColor ? w->bgColor : colors->contentBg;

    // Sunken border -- highlight/shadow are swapped vs raised bevel
    // to create the "pressed in" trough appearance
    BevelStyleT bevel;
    bevel.highlight = colors->windowShadow;
    bevel.shadow    = colors->windowHighlight;
    bevel.face      = bg;
    bevel.width     = 2;
    drawBevel(disp, ops, w->x, w->y, w->w, w->h, &bevel);

    // Fill bar
    int32_t maxVal = d->maxValue;

    if (maxVal <= 0) {
        maxVal = 100;
    }

    int32_t innerW = w->w - 4;
    int32_t innerH = w->h - 4;

    if (d->vertical) {
        int32_t fillH = (innerH * d->value) / maxVal;

        if (fillH > innerH) {
            fillH = innerH;
        }

        if (fillH > 0) {
            rectFill(disp, ops, w->x + 2, w->y + 2 + innerH - fillH, innerW, fillH, fg);
        }
    } else {
        int32_t fillW = (innerW * d->value) / maxVal;

        if (fillW > innerW) {
            fillW = innerW;
        }

        if (fillW > 0) {
            rectFill(disp, ops, w->x + 2, w->y + 2, fillW, innerH, fg);
        }
    }
}


// ============================================================
// widgetProgressBarDestroy
// ============================================================

void widgetProgressBarDestroy(WidgetT *w) {
    free(w->data);
}


// ============================================================
// DXE registration
// ============================================================

static const WidgetClassT sClassProgressBar = {
    .version = WGT_CLASS_VERSION,
    .flags   = 0,
    .handlers = {
        [WGT_METHOD_PAINT]         = (void *)widgetProgressBarPaint,
        [WGT_METHOD_CALC_MIN_SIZE] = (void *)widgetProgressBarCalcMinSize,
        [WGT_METHOD_DESTROY]       = (void *)widgetProgressBarDestroy,
    }
};


// ============================================================
// Widget creation functions
// ============================================================


WidgetT *wgtProgressBar(WidgetT *parent) {
    WidgetT *w = widgetAlloc(parent, sTypeId);

    if (w) {
        ProgressBarDataT *d = calloc(1, sizeof(ProgressBarDataT));
        d->value    = 0;
        d->maxValue = 100;
        d->vertical = false;
        w->data     = d;
    }

    return w;
}


WidgetT *wgtProgressBarV(WidgetT *parent) {
    WidgetT *w = widgetAlloc(parent, sTypeId);

    if (w) {
        ProgressBarDataT *d = calloc(1, sizeof(ProgressBarDataT));
        d->value    = 0;
        d->maxValue = 100;
        d->vertical = true;
        w->data     = d;
    }

    return w;
}


int32_t wgtProgressBarGetValue(const WidgetT *w) {
    VALIDATE_WIDGET(w, sTypeId, 0);
    ProgressBarDataT *d = (ProgressBarDataT *)w->data;

    return d->value;
}


void wgtProgressBarSetValue(WidgetT *w, int32_t value) {
    VALIDATE_WIDGET_VOID(w, sTypeId);
    ProgressBarDataT *d = (ProgressBarDataT *)w->data;

    if (value < 0) {
        value = 0;
    }

    if (value > d->maxValue) {
        value = d->maxValue;
    }

    d->value = value;
    wgtInvalidatePaint(w);
}


// ============================================================
// DXE registration
// ============================================================


static const struct {
    WidgetT *(*create)(WidgetT *parent);
    WidgetT *(*createV)(WidgetT *parent);
    void     (*setValue)(WidgetT *w, int32_t value);
    int32_t  (*getValue)(const WidgetT *w);
} sApi = {
    .create   = wgtProgressBar,
    .createV  = wgtProgressBarV,
    .setValue  = wgtProgressBarSetValue,
    .getValue = wgtProgressBarGetValue
};

static const WgtPropDescT sProps[] = {
    { "Value", WGT_IFACE_INT, (void *)wgtProgressBarGetValue, (void *)wgtProgressBarSetValue }
};

static const WgtIfaceT sIface = {
    .basName     = "ProgressBar",
    .props       = sProps,
    .propCount   = 1,
    .methods     = NULL,
    .methodCount = 0,
    .events      = NULL,
    .eventCount  = 0
};

void wgtRegister(void) {
    sTypeId = wgtRegisterClass(&sClassProgressBar);
    wgtRegisterApi("progressbar", &sApi);
    wgtRegisterIface("progressbar", &sIface);
}