diff options
| -rw-r--r-- | draw.go | 47 |
1 files changed, 43 insertions, 4 deletions
@@ -89,11 +89,11 @@ package ui // free(desc); // return font; // } -// static uiDrawTextLayout *newTextLayout(char *text, uiDrawTextFont *defaultFont) +// static uiDrawTextLayout *newTextLayout(char *text, uiDrawTextFont *defaultFont, double width) // { // uiDrawTextLayout *layout; // -// layout = uiDrawNewTextLayout(text, defaultFont); +// layout = uiDrawNewTextLayout(text, defaultFont, width); // free(text); // return layout; // } @@ -109,6 +109,19 @@ package ui // { // free(m); // } +// static double *newDouble(void) +// { +// double *d; +// +// d = (double *) malloc(sizeof (double)); +// // TODO +// return d; +// } +// static void freeDoubles(double *a, double *b) +// { +// free(a); +// free(b); +// } 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.) @@ -763,15 +776,19 @@ func (f *Font) Metrics() *FontMetrics { // 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. +// +// The block of text can either be a single line or multiple +// word-wrapped lines, each with a given maximum width. type TextLayout struct { l *C.uiDrawTextLayout } // NewTextLayout creates a new TextLayout. -func NewTextLayout(text string, defaultFont *Font) *TextLayout { +// For details on the width parameter, see SetWidth. +func NewTextLayout(text string, defaultFont *Font, width float64) *TextLayout { l := new(TextLayout) ctext := C.CString(text) // freed by C.newTextLayout() - l.l = C.newTextLayout(ctext, defaultFont.f) + l.l = C.newTextLayout(ctext, defaultFont.f, C.double(width)) return l } @@ -781,6 +798,28 @@ func (l *TextLayout) Free() { C.uiDrawFreeTextLayout(l.l) } +// SetWidth sets the maximum width of the lines of text in a +// TextLayout. If the given width is negative, then the TextLayout +// will draw as a single line of text instead. +func (l *TextLayout) SetWidth(width float64) { + C.uiDrawTextLayoutSetWidth(l.l, C.double(width)) +} + +// Extents returns the width and height that the TextLayout will +// actually take up when drawn. This measures full line allocations, +// even if no glyph reaches to the top of its ascent or bottom of its +// descent; it does not return a "best fit" rectnagle for the points that +// are actually drawn. +func (l *TextLayout) Extents() (width float64, height float64) { + cwidth := C.newDouble() + cheight := C.newDouble() + C.uiDrawTextLayoutExtents(l.l, cwidth, cheight) + width = float64(*cwidth) + height = float64(*cheight) + C.freeDoubles(cwidth, cheight) + return width, height +} + // 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?) |