libui/unix/attrstr.c

// 12 february 2017
#include "uipriv_unix.h"
#include "attrstr.h"

// TODO pango alpha attributes turn 0 into 65535 :|

// TODO make this name less generic?
struct foreachParams {
	PangoAttrList *attrs;
	// TODO use pango's built-in background attribute
	GPtrArray *backgroundParams;
};

static void backgroundClosure(uiDrawContext *c, uiDrawTextLayout *layout, double x, double y, gpointer data)
{
	struct closureParams *p = (struct closureParams *) data;
	uiDrawBrush brush;

	brush.Type = uiDrawBrushTypeSolid;
	brush.R = p->r;
	brush.G = p->g;
	brush.B = p->b;
	brush.A = p->a;
//TODO	drawTextBackground(c, x, y, layout, p->start, p->end, &brush, 0);
}

static void addBackgroundAttribute(struct foreachParams *p, size_t start, size_t end, double r, double g, double b, double a)
{
	uiprivDrawTextBackgroundParams *dtb;

	dtb = uiprivNew(uiprivDrawTextBackgroundParams);
	dtb->start = start;
	dtb->end = end;
	dtb->r = r;
	dtb->g = g;
	dtb->b = b;
	dtb->a = a;
	g_ptr_array_add(p->backgroundParams, dtb);
}

static void addattr(struct foreachParams *p, size_t start, size_t end, PangoAttribute *attr)
{
	if (attr == NULL)		// in case of a future attribute
		return;
	attr->start_index = start;
	attr->end_index = end;
	pango_attr_list_insert(p->attrs, attr);
}

static uiForEach processAttribute(const uiAttributedString *s, const uiAttribute *attr, size_t start, size_t end, void *data)
{
	struct foreachParams *p = (struct foreachParams *) data;
	double r, g, b, a;
	PangoUnderline underline;
	uiUnderlineColor colorType;
	const uiOpenTypeFeatures *features;
	GString *featurestr;

	switch (uiAttributeGetType(attr)) {
	case uiAttributeTypeFamily:
		addattr(p, start, end,
			pango_attr_family_new(uiAttributeFamily(attr)));
		break;
	case uiAttributeTypeSize:
		addattr(p, start, end,
			pango_attr_size_new(cairoToPango(uiAttributeSize(attr))));
		break;
	case uiAttributeTypeWeight:
		// TODO reverse the misalignment from drawtext.c if it is corrected 
		addattr(p, start, end,
			pango_attr_weight_new((PangoWeight) uiAttributeWeight(attr)));
		break;
	case uiAttributeTypeItalic:
		addattr(p, start, end,
			pango_attr_style_new(pangoItalics[uiAttributeItalic(attr)]));
		break;
	case uiAttributeTypeStretch:
		addattr(p, start, end,
			pango_attr_stretch_new(pangoStretches[uiAttributeStretch(attr)]));
		break;
	case uiAttributeTypeColor:
		uiAttributeColor(attr, &r, &g, &b, &a);
		addattr(p, start, end,
			pango_attr_foreground_new(
				(guint16) (r * 65535.0),
				(guint16) (g * 65535.0),
				(guint16) (b * 65535.0)));
		addattr(p, start, end,
			FUTURE_pango_attr_foreground_alpha_new(
				(guint16) (a * 65535.0)));
		break;
	case uiAttributeTypeBackground:
		uiAttributeColor(attr, &r, &g, &b, &a);
		addBackgroundAttribute(p, start, end, r, g, b, a);
		break;
	case uiAttributeTypeUnderline:
		switch (uiAttributeUnderline(attr)) {
		case uiUnderlineNone:
			underline = PANGO_UNDERLINE_NONE;
			break;
		case uiUnderlineSingle:
			underline = PANGO_UNDERLINE_SINGLE;
			break;
		case uiUnderlineDouble:
			underline = PANGO_UNDERLINE_DOUBLE;
			break;
		case uiUnderlineSuggestion:
			underline = PANGO_UNDERLINE_ERROR;
			break;
		}
		addattr(p, start, end,
			pango_attr_underline_new(underline));
		break;
	case uiAttributeTypeUnderlineColor:
		uiAttributeUnderlineColor(attr, &colorType, &r, &g, &b, &a);
		switch (colorType) {
		case uiUnderlineColorCustom:
			addattr(p, start, end,
				pango_attr_underline_color_new(
					(guint16) (r * 65535.0),
					(guint16) (g * 65535.0),
					(guint16) (b * 65535.0)));
			break;
		case uiUnderlineColorSpelling:
			// TODO GtkTextView style property error-underline-color
			addattr(p, start, end,
				pango_attr_underline_color_new(65535, 0, 0));
			break;
		case uiUnderlineColorGrammar:
			// TODO find a more appropriate color
			addattr(p, start, end,
				pango_attr_underline_color_new(0, 65535, 0));
			break;
		case uiUnderlineColorAuxiliary:
			// TODO find a more appropriate color
			addattr(p, start, end,
				pango_attr_underline_color_new(0, 0, 65535));
			break;
		}
		break;
	case uiAttributeTypeFeatures:
		// only generate an attribute if the features object is not NULL
		// TODO state that this is allowed
		features = uiAttributeFeatures(attr);
		if (features == NULL)
			break;
		featurestr = uiprivOpenTypeFeaturesToPangoCSSFeaturesString(features);
		addattr(p, start, end,
			FUTURE_pango_attr_font_features_new(featurestr->str));
		g_string_free(featurestr, TRUE);
		break;
	default:
		// TODO complain
		;
	}
	return uiForEachContinue;
}

static void freeBackgroundParams(gpointer data)
{
	uiprivFree((uiprivDrawTextBackgroundParams *) data);
}

PangoAttrList *uiprivAttributedStringToPangoAttrList(uiDrawTextLayoutParams *p, GPtrArray **backgroundParams)
{
	struct foreachParams fep;

	fep.attrs = pango_attr_list_new();
	fep.backgroundParams = g_ptr_array_new_with_free_func(freeBackgroundParams);
	uiAttributedStringForEachAttribute(p->String, processAttribute, &fep);
	*backgroundParams = fep.backgroundParams;
	return fep.attrs;
}