DVX_GUI/widgets/widgetImageButton.c

#define DVX_WIDGET_IMPL
// widgetImageButton.c  -- Image button widget (button with image instead of text)
//
// Combines a Button's beveled border and press behavior with an Image's
// bitmap rendering. The image is centered within the button bounds and
// shifts by 1px on press, just like text in a regular button.
//
// Uses the same two-phase press model as Button: mouse press stores in
// sPressedButton, keyboard press (Space/Enter) stores in sKeyPressedBtn,
// and the event dispatcher handles release/cancel. The onClick callback
// fires on release, not press.
//
// The widget takes ownership of the image data buffer  -- if widget creation
// fails, the data is freed to prevent leaks.
//
// The 4px added to min size (widgetImageButtonCalcMinSize) accounts for
// the 2px bevel on each side  -- no extra padding is added beyond that,
// keeping image buttons compact for toolbar use.

#include "dvxWidgetPlugin.h"

static int32_t sTypeId = -1;

typedef struct {
    uint8_t *pixelData;
    int32_t  imgW;
    int32_t  imgH;
    int32_t  imgPitch;
    bool     pressed;
} ImageButtonDataT;


// ============================================================
// widgetImageButtonDestroy
// ============================================================

void widgetImageButtonDestroy(WidgetT *w) {
    ImageButtonDataT *d = (ImageButtonDataT *)w->data;

    if (d) {
        free(d->pixelData);
        free(d);
    }
}


// ============================================================
// widgetImageButtonCalcMinSize
// ============================================================

void widgetImageButtonCalcMinSize(WidgetT *w, const BitmapFontT *font) {
    (void)font;
    ImageButtonDataT *d = (ImageButtonDataT *)w->data;

    // Bevel border only, no extra padding
    w->calcMinW = d->imgW + 4;
    w->calcMinH = d->imgH + 4;
}


// ============================================================
// widgetImageButtonOnKey
// ============================================================

void widgetImageButtonOnKey(WidgetT *w, int32_t key, int32_t mod) {
    (void)mod;
    ImageButtonDataT *d = (ImageButtonDataT *)w->data;

    if (key == ' ' || key == 0x0D) {
        d->pressed = true;
        sKeyPressedBtn = w;
        wgtInvalidatePaint(w);
    }
}


// ============================================================
// widgetImageButtonOnMouse
// ============================================================

void widgetImageButtonOnMouse(WidgetT *w, WidgetT *root, int32_t vx, int32_t vy) {
    (void)root;
    (void)vx;
    (void)vy;
    ImageButtonDataT *d = (ImageButtonDataT *)w->data;
    w->focused = true;
    d->pressed = true;
    sPressedButton = w;
}


// ============================================================
// widgetImageButtonPaint
// ============================================================

void widgetImageButtonPaint(WidgetT *w, DisplayT *disp, const BlitOpsT *ops, const BitmapFontT *font, const ColorSchemeT *colors) {
    (void)font;
    ImageButtonDataT *d = (ImageButtonDataT *)w->data;

    uint32_t bgFace = w->bgColor ? w->bgColor : colors->buttonFace;
    bool     pressed = d->pressed && w->enabled;

    BevelStyleT bevel;
    bevel.highlight = pressed ? colors->windowShadow : colors->windowHighlight;
    bevel.shadow    = pressed ? colors->windowHighlight : colors->windowShadow;
    bevel.face      = bgFace;
    bevel.width     = 2;
    drawBevel(disp, ops, w->x, w->y, w->w, w->h, &bevel);

    if (d->pixelData) {
        int32_t imgX = w->x + (w->w - d->imgW) / 2;
        int32_t imgY = w->y + (w->h - d->imgH) / 2;

        if (pressed) {
            imgX++;
            imgY++;
        }

        rectCopy(disp, ops, imgX, imgY,
                 d->pixelData, d->imgPitch,
                 0, 0, d->imgW, d->imgH);
    }

    if (w->focused) {
        uint32_t fg  = w->fgColor ? w->fgColor : colors->contentFg;
        int32_t  off = pressed ? 1 : 0;
        drawFocusRect(disp, ops, w->x + 3 + off, w->y + 3 + off, w->w - 6, w->h - 6, fg);
    }
}


// ============================================================
// widgetImageButtonAccelActivate
// ============================================================

void widgetImageButtonAccelActivate(WidgetT *w, WidgetT *root) {
    (void)root;
    ImageButtonDataT *d = (ImageButtonDataT *)w->data;
    d->pressed = true;
    sKeyPressedBtn = w;
    wgtInvalidatePaint(w);
}


// ============================================================
// widgetImageButtonSetPressed
// ============================================================

void widgetImageButtonSetPressed(WidgetT *w, bool pressed) {
    ImageButtonDataT *d = (ImageButtonDataT *)w->data;
    d->pressed = pressed;
    wgtInvalidatePaint(w);
}


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

static const WidgetClassT sClassImageButton = {
    .flags           = WCLASS_FOCUSABLE | WCLASS_PRESS_RELEASE,
    .paint           = widgetImageButtonPaint,
    .paintOverlay    = NULL,
    .calcMinSize     = widgetImageButtonCalcMinSize,
    .layout          = NULL,
    .onMouse         = widgetImageButtonOnMouse,
    .onKey           = widgetImageButtonOnKey,
    .onAccelActivate = widgetImageButtonAccelActivate,
    .destroy         = widgetImageButtonDestroy,
    .getText         = NULL,
    .setText         = NULL,
    .setPressed      = widgetImageButtonSetPressed
};


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


WidgetT *wgtImageButton(WidgetT *parent, uint8_t *pixelData, int32_t w, int32_t h, int32_t pitch) {
    if (!parent || !pixelData || w <= 0 || h <= 0) {
        return NULL;
    }

    WidgetT *wgt = widgetAlloc(parent, sTypeId);

    if (wgt) {
        ImageButtonDataT *d = calloc(1, sizeof(ImageButtonDataT));
        d->pixelData = pixelData;
        d->imgW      = w;
        d->imgH      = h;
        d->imgPitch  = pitch;
        d->pressed   = false;
        wgt->data    = d;
    } else {
        free(pixelData);
    }

    return wgt;
}


WidgetT *wgtImageButtonFromFile(WidgetT *parent, const char *path) {
    if (!parent || !path) {
        return NULL;
    }

    AppContextT *ctx = wgtGetContext(parent);

    if (!ctx) {
        return NULL;
    }

    int32_t  imgW;
    int32_t  imgH;
    int32_t  pitch;
    uint8_t *buf = dvxLoadImage(ctx, path, &imgW, &imgH, &pitch);

    if (!buf) {
        return NULL;
    }

    return wgtImageButton(parent, buf, imgW, imgH, pitch);
}


void wgtImageButtonSetData(WidgetT *w, uint8_t *pixelData, int32_t imgW, int32_t imgH, int32_t pitch) {
    VALIDATE_WIDGET_VOID(w, sTypeId);
    ImageButtonDataT *d = (ImageButtonDataT *)w->data;

    free(d->pixelData);
    d->pixelData = pixelData;
    d->imgW      = imgW;
    d->imgH      = imgH;
    d->imgPitch  = pitch;
    wgtInvalidate(w);
}


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


static const struct {
    WidgetT *(*create)(WidgetT *parent, uint8_t *pixelData, int32_t w, int32_t h, int32_t pitch);
    WidgetT *(*fromFile)(WidgetT *parent, const char *path);
    void     (*setData)(WidgetT *w, uint8_t *pixelData, int32_t imgW, int32_t imgH, int32_t pitch);
} sApi = {
    .create   = wgtImageButton,
    .fromFile = wgtImageButtonFromFile,
    .setData  = wgtImageButtonSetData
};

void wgtRegister(void) {
    sTypeId = wgtRegisterClass(&sClassImageButton);
    wgtRegisterApi("imagebutton", &sApi);
}