label.c

/*
 * Twin - A Tiny Window System
 * Copyright (c) 2004 Keith Packard <keithp@keithp.com>
 * All rights reserved.
 */

#include <stdlib.h>

#include "twin_private.h"

static void _twin_label_query_geometry(twin_label_t *label)
{
    twin_path_t *path = twin_path_create();
    twin_text_metrics_t m;

    label->widget.preferred.width = twin_fixed_to_int(label->font_size) * 2;
    label->widget.preferred.height = twin_fixed_to_int(label->font_size) * 2;
    if (path) {
        twin_path_set_font_size(path, label->font_size);
        twin_path_set_font_style(path, label->font_style);
        twin_text_metrics_utf8(path, label->label, &m);
        label->widget.preferred.width += twin_fixed_to_int(m.width);
        twin_path_destroy(path);
    }
}

static void _twin_label_paint(twin_label_t *label)
{
    twin_path_t *path = twin_path_create();
    twin_text_metrics_t m;
    twin_coord_t w = _twin_widget_width(label);
    twin_coord_t h = _twin_widget_height(label);

    if (path) {
        twin_fixed_t wf = twin_int_to_fixed(w);
        twin_fixed_t hf = twin_int_to_fixed(h);
        twin_fixed_t x = 0, y;

        twin_path_set_font_size(path, label->font_size);
        twin_path_set_font_style(path, label->font_style);
        twin_text_metrics_utf8(path, label->label, &m);
        y = (hf - (m.ascent + m.descent)) / 2 + m.ascent + label->offset.y;
        switch (label->align) {
        case TwinAlignLeft:
            x = label->font_size / 2;
            break;
        case TwinAlignCenter:
            x = (wf - m.width) / 2;
            break;
        case TwinAlignRight:
            x = wf - label->font_size / 2 - m.width;
            break;
        }
        x += label->offset.x;
        twin_path_move(path, x, y);
        twin_path_utf8(path, label->label);
        twin_paint_path(label->widget.window->pixmap, label->foreground, path);
        twin_path_destroy(path);
    }
}

twin_dispatch_result_t _twin_label_dispatch(twin_widget_t *widget,
                                            twin_event_t *event)
{
    twin_label_t *label = (twin_label_t *) widget;

    if (_twin_widget_dispatch(widget, event) == TwinDispatchDone)
        return TwinDispatchDone;
    switch (event->kind) {
    case TwinEventPaint:
        _twin_label_paint(label);
        break;
    case TwinEventQueryGeometry:
        _twin_label_query_geometry(label);
        break;
    default:
        break;
    }
    return TwinDispatchContinue;
}

void twin_label_set(twin_label_t *label,
                    const char *value,
                    twin_argb32_t foreground,
                    twin_fixed_t font_size,
                    twin_style_t font_style)
{
    if (value) {
        char *new = malloc(strlen(value) + 1);

        if (new) {
            if (label->label)
                free(label->label);
            label->label = new;
            strcpy(label->label, value);
        }
    }
    label->font_size = font_size;
    label->font_style = font_style;
    label->foreground = foreground;
    _twin_widget_queue_layout(&label->widget);
}

void _twin_label_init(twin_label_t *label,
                      twin_box_t *parent,
                      const char *value,
                      twin_argb32_t foreground,
                      twin_fixed_t font_size,
                      twin_style_t font_style,
                      twin_dispatch_proc_t dispatch)
{
    static const twin_widget_layout_t preferred = {0, 0, 1, 1};
    _twin_widget_init(&label->widget, parent, 0, preferred, dispatch);
    label->label = NULL;
    label->offset.x = 0;
    label->offset.y = 0;
    label->align = TwinAlignCenter;
    twin_label_set(label, value, foreground, font_size, font_style);
}


twin_label_t *twin_label_create(twin_box_t *parent,
                                const char *value,
                                twin_argb32_t foreground,
                                twin_fixed_t font_size,
                                twin_style_t font_style)
{
    twin_label_t *label = malloc(sizeof(twin_label_t));
    if (!label)
        return NULL;

    _twin_label_init(label, parent, value, foreground, font_size, font_style,
                     _twin_label_dispatch);
    return label;
}