diff options
| -rw-r--r-- | draw.go | 147 |
1 files changed, 147 insertions, 0 deletions
@@ -72,6 +72,24 @@ package ui // { // free(m); // } +// static uiDrawInitialTextStyle *newInitialTextStyle(void) +// { +// uiDrawInitialTextStyle *is; +// +// is = (uiDrawInitialTextStyle *) malloc(sizeof (uiDrawInitialTextStyle)); +// // TODO +// return is; +// } +// static uiDrawTextLayout *newTextLayout(char *text, uiDrawInitialTextStyle *is) +// { +// uiDrawTextLayout *layout; +// +// layout = uiDrawNewTextLayout(text, is); +// free(text); +// free((char *) (is->Family)); +// free(is); +// return layout; +// } import "C" // BUG(andlabs): Ideally, all the drawing APIs should be in another package ui/draw (they all have the "uiDraw" prefix in C to achieve a similar goal of avoiding confusing programmers via namespace pollution); managing the linkage of the libui shared library itself across multiple packages is likely going to be a pain, though. (Custom controls implemented using libui won't have this issue, as they *should* only need libui present when linking the shared object, not when linking the Go wrapper. I'm not sure; I'd have to find out first.) @@ -112,6 +130,8 @@ type Path struct { } // TODO +// +// TODO disclaimer type FillMode uint const ( Winding FillMode = iota @@ -543,3 +563,130 @@ func (f *FontFamilies) Family(n int) string { C.uiFreeText(cname) return name } + +// TextWeight defines the various text weights, in order of +// increasing weight. +// +// Note that if you leave this field unset, it will default to +// TextWeightThin. If you want the normal font weight, explicitly +// use the constant TextWeightNormal instead. +// TODO realign these? +// +// TODO disclaimer +type TextWeight int +const ( + TextWeightThin TextWeight = iota + TextWeightUltraLight + TextWeightLight + TextWeightBook + TextWeightNormal + TextWeightMedium + TextWeightSemiBold + TextWeightBold + TextWeightUtraBold + TextWeightHeavy + TextWeightUltraHeavy +) + +// TextItalic defines the various text italic modes. +// +// TODO disclaimer +type TextItalic int +const ( + TextItalicNormal TextItalic = iota + TextItalicOblique // merely slanted text + TextItalicItalic // true italics +) + +// TextStretch defines the various text stretches, in order of +// increasing wideness. +// +// Note that if you leave this field unset, it will default to +// TextStretchUltraCondensed. If you want the normal font +// stretch, explicitly use the constant TextStretchNormal +// instead. +// TODO realign these? +// +// TODO disclaimer +type TextStretch int +const ( + TextStretchUltraCondensed TextStretch = iota + TextStretchExtraCondensed + TextStretchCondensed + TextStretchSemiCondensed + TextStretchNormal + TextStretchSemiExpanded + TextStretchExpanded + TextStretchExtraExpanded + TextStretchUltraExpanded +) + +// TODO put TextGravity here + +// InitialTextStyle defines the text font and style that a TextLayout +// initially takes. Characters in the TextLayout that do not have any +// attributes applied will use this style. (Attributes that are not fields +// of this structure have default values specified in their method +// descriptions.) +// +// If the requested text style is not available on the system, the +// closest matching font is used. This means that, for instance, +// if you specify a Weight of TextWeightUltraHeavy and the +// heaviest weight available for the chosen font family is actually +// TextWeightBold, that will be used instead. The specific details +// of font matching beyond this description are implementation +// defined. +// +// TODO rename this TextFontDescriptor? +type InitialTextStyle struct { + Family string + Size float64 // as a text size, for instance 12 for a 12-point font + Weight TextWeight + Italic TextItalic + SmallCaps bool + Stretch TextStretch + // TODO gravity +} + +// TextLayout is the entry point for formatting a block of text to be +// drawn onto a DrawContext. +// +// The block of text to lay out and the initial attributes are provided +// at TextLayout creation time and cannot be changed later. +// However, you may add attributes to various points of the text +// at any time, even after drawing the text once (unlike a DrawPath). +// Some of these attributes also have initial values; refer to each +// method to see what they are. +type TextLayout struct { + l *C.uiDrawTextLayout +} + +// NewTextLayout creates a new TextLayout. +func NewTextLayout(text string, initialStyle *InitialTextStyle) *TextLayout { + l := new(TextLayout) + ctext := C.CString(text) // all three of these are cleaned up by C.newTextLayout() + is := C.newInitialTextStyle() + is.Family = C.CString(initialStyle.Family) + is.Size = C.double(initialStyle.Size) + is.Weight = C.uiDrawTextWeight(initialStyle.Weight) + is.Italic = C.uiDrawTextItalic(initialStyle.Italic) + is.SmallCaps = frombool(initialStyle.SmallCaps) + is.Stretch = C.uiDrawTextStretch(initialStyle.Stretch) +// is.Gravity = C.uiDrawTextGravity(initialStyle.Gravity) + is.Gravity = C.uiDrawTextGravitySouth + l.l = C.newTextLayout(ctext, is) + return l +} + +// Free destroys a TextLayout. After calling Free the TextLayout +// cannot be used. +func (l *TextLayout) Free() { + C.uiDrawFreeTextLayout(l.l) +} + +// Text draws the given TextLayout onto c at the given point. +// The point refers to the top-left corner of the text. +// (TODO bounding box or typographical extent?) +func (c *DrawContext) Text(x float64, y float64, layout *TextLayout) { + C.uiDrawText(c.c, C.double(x), C.double(y), layout.l) +} |