DVX_GUI/dvx/widgets/widgetTextInput.c

// widgetTextInput.c — TextInput and TextArea widgets

#include "widgetInternal.h"


// ============================================================
// wgtTextArea
// ============================================================

WidgetT *wgtTextArea(WidgetT *parent, int32_t maxLen) {
    WidgetT *w = widgetAlloc(parent, WidgetTextAreaE);

    if (w) {
        int32_t bufSize = maxLen > 0 ? maxLen + 1 : 256;
        w->as.textArea.buf     = (char *)malloc(bufSize);
        w->as.textArea.bufSize = bufSize;

        if (w->as.textArea.buf) {
            w->as.textArea.buf[0] = '\0';
        }
    }

    return w;
}


// ============================================================
// widgetTextAreaDestroy
// ============================================================

void widgetTextAreaDestroy(WidgetT *w) {
    free(w->as.textArea.buf);
}


// ============================================================
// wgtTextInput
// ============================================================

WidgetT *wgtTextInput(WidgetT *parent, int32_t maxLen) {
    WidgetT *w = widgetAlloc(parent, WidgetTextInputE);

    if (w) {
        int32_t bufSize = maxLen > 0 ? maxLen + 1 : 256;
        w->as.textInput.buf     = (char *)malloc(bufSize);
        w->as.textInput.bufSize = bufSize;

        if (w->as.textInput.buf) {
            w->as.textInput.buf[0] = '\0';
        }

        w->weight = 100;  // text inputs stretch by default
    }

    return w;
}


// ============================================================
// widgetTextInputDestroy
// ============================================================

void widgetTextInputDestroy(WidgetT *w) {
    free(w->as.textInput.buf);
}


// ============================================================
// widgetTextInputGetText
// ============================================================

const char *widgetTextInputGetText(const WidgetT *w) {
    return w->as.textInput.buf ? w->as.textInput.buf : "";
}


// ============================================================
// widgetTextInputSetText
// ============================================================

void widgetTextInputSetText(WidgetT *w, const char *text) {
    if (w->as.textInput.buf) {
        strncpy(w->as.textInput.buf, text, w->as.textInput.bufSize - 1);
        w->as.textInput.buf[w->as.textInput.bufSize - 1] = '\0';
        w->as.textInput.len       = (int32_t)strlen(w->as.textInput.buf);
        w->as.textInput.cursorPos = w->as.textInput.len;
        w->as.textInput.scrollOff = 0;
    }
}


// ============================================================
// widgetTextInputCalcMinSize
// ============================================================

void widgetTextInputCalcMinSize(WidgetT *w, const BitmapFontT *font) {
    w->calcMinW = font->charWidth * 8 + TEXT_INPUT_PAD * 2;
    w->calcMinH = font->charHeight + TEXT_INPUT_PAD * 2;
}


// ============================================================
// widgetTextInputOnMouse
// ============================================================

void widgetTextInputOnMouse(WidgetT *w, WidgetT *root, int32_t vx, int32_t vy) {
    (void)vy;
    w->focused = true;

    // Place cursor at click position
    AppContextT *ctx = (AppContextT *)root->userData;
    const BitmapFontT *font = &ctx->font;
    int32_t relX    = vx - w->x - TEXT_INPUT_PAD;
    int32_t charPos = relX / font->charWidth + w->as.textInput.scrollOff;

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

    if (charPos > w->as.textInput.len) {
        charPos = w->as.textInput.len;
    }

    w->as.textInput.cursorPos = charPos;
}


// ============================================================
// widgetTextEditOnKey — shared text editing logic
// ============================================================

void widgetTextEditOnKey(WidgetT *w, int32_t key, char *buf, int32_t bufSize, int32_t *pLen, int32_t *pCursor, int32_t *pScrollOff) {
    if (key >= 32 && key < 127) {
        // Printable character
        if (*pLen < bufSize - 1) {
            int32_t pos = *pCursor;

            memmove(buf + pos + 1, buf + pos, *pLen - pos + 1);
            buf[pos] = (char)key;
            (*pLen)++;
            (*pCursor)++;

            if (w->onChange) {
                w->onChange(w);
            }
        }
    } else if (key == 8) {
        // Backspace
        if (*pCursor > 0) {
            int32_t pos = *pCursor;

            memmove(buf + pos - 1, buf + pos, *pLen - pos + 1);
            (*pLen)--;
            (*pCursor)--;

            if (w->onChange) {
                w->onChange(w);
            }
        }
    } else if (key == (0x4B | 0x100)) {
        // Left arrow
        if (*pCursor > 0) {
            (*pCursor)--;
        }
    } else if (key == (0x4D | 0x100)) {
        // Right arrow
        if (*pCursor < *pLen) {
            (*pCursor)++;
        }
    } else if (key == (0x47 | 0x100)) {
        // Home
        *pCursor = 0;
    } else if (key == (0x4F | 0x100)) {
        // End
        *pCursor = *pLen;
    } else if (key == (0x53 | 0x100)) {
        // Delete
        if (*pCursor < *pLen) {
            int32_t pos = *pCursor;

            memmove(buf + pos, buf + pos + 1, *pLen - pos);
            (*pLen)--;

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

    // Adjust scroll offset to keep cursor visible
    AppContextT *ctx = (AppContextT *)w->window->widgetRoot->userData;
    const BitmapFontT *font = &ctx->font;
    int32_t fieldW = w->w;

    if (w->type == WidgetComboBoxE) {
        fieldW -= DROPDOWN_BTN_WIDTH;
    }

    int32_t visibleChars = (fieldW - TEXT_INPUT_PAD * 2) / font->charWidth;

    if (*pCursor < *pScrollOff) {
        *pScrollOff = *pCursor;
    }

    if (*pCursor >= *pScrollOff + visibleChars) {
        *pScrollOff = *pCursor - visibleChars + 1;
    }

    wgtInvalidate(w);
}


// ============================================================
// widgetTextInputOnKey
// ============================================================

void widgetTextInputOnKey(WidgetT *w, int32_t key) {
    if (!w->as.textInput.buf) {
        return;
    }

    widgetTextEditOnKey(w, key, w->as.textInput.buf, w->as.textInput.bufSize,
                        &w->as.textInput.len, &w->as.textInput.cursorPos,
                        &w->as.textInput.scrollOff);
}


// ============================================================
// widgetTextInputPaint
// ============================================================

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

    // Sunken border
    BevelStyleT bevel;
    bevel.highlight = colors->windowShadow;
    bevel.shadow    = colors->windowHighlight;
    bevel.face      = bg;
    bevel.width     = 2;
    drawBevel(d, ops, w->x, w->y, w->w, w->h, &bevel);

    // Draw text
    if (w->as.textInput.buf) {
        int32_t textX    = w->x + TEXT_INPUT_PAD;
        int32_t textY    = w->y + (w->h - font->charHeight) / 2;
        int32_t maxChars = (w->w - TEXT_INPUT_PAD * 2) / font->charWidth;
        int32_t off      = w->as.textInput.scrollOff;
        int32_t len      = w->as.textInput.len - off;

        if (len > maxChars) {
            len = maxChars;
        }

        for (int32_t i = 0; i < len; i++) {
            drawChar(d, ops, font, textX + i * font->charWidth, textY,
                     w->as.textInput.buf[off + i],
                     fg, bg, true);
        }

        // Draw cursor
        if (w->focused) {
            int32_t cursorX = textX + (w->as.textInput.cursorPos - off) * font->charWidth;

            if (cursorX >= w->x + TEXT_INPUT_PAD &&
                cursorX < w->x + w->w - TEXT_INPUT_PAD) {
                drawVLine(d, ops, cursorX, textY, font->charHeight, fg);
            }
        }
    }
}