diff options
Diffstat (limited to 'draw.go')
| -rw-r--r-- | draw.go | 119 |
1 files changed, 82 insertions, 37 deletions
@@ -72,22 +72,29 @@ package ui // { // free(m); // } -// static uiDrawInitialTextStyle *newInitialTextStyle(void) +// static uiDrawTextFontDescriptor *newFontDescriptor(void) // { -// uiDrawInitialTextStyle *is; +// uiDrawTextFontDescriptor *desc; // -// is = (uiDrawInitialTextStyle *) malloc(sizeof (uiDrawInitialTextStyle)); +// desc = (uiDrawTextFontDescriptor *) malloc(sizeof (uiDrawTextFontDescriptor)); // // TODO -// return is; +// return desc; // } -// static uiDrawTextLayout *newTextLayout(char *text, uiDrawInitialTextStyle *is) +// static uiDrawTextFont *newFont(uiDrawTextFontDescriptor *desc) +// { +// uiDrawTextFont *font; +// +// font = uiDrawLoadClosestFont(desc); +// free((char *) (desc->Family)); +// free(desc); +// return font; +// } +// static uiDrawTextLayout *newTextLayout(char *text, uiDrawTextFont *defaultFont) // { // uiDrawTextLayout *layout; // -// layout = uiDrawNewTextLayout(text, is); +// layout = uiDrawNewTextLayout(text, defaultFont); // free(text); -// free((char *) (is->Family)); -// free(is); // return layout; // } import "C" @@ -623,22 +630,8 @@ const ( // 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 { +// FontDescriptor describes a Font. +type FontDescriptor struct { Family string Size float64 // as a text size, for instance 12 for a 12-point font Weight TextWeight @@ -648,10 +641,71 @@ type InitialTextStyle struct { // TODO gravity } +// Font represents an actual font that can be drawn with. +type Font struct { + f *C.uiDrawTextFont +} + +// LoadClosestFont loads a Font. +// +// You pass the properties of the ideal font you want to load in the +// FontDescriptor you pass to this function. 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. This also means that +// getting a descriptor back out of a Font may return a different +// desriptor. +// +// TODO guarantee that passing *that* back into LoadClosestFont() returns the same font +func LoadClosestFont(desc *FontDescriptor) *Font { + d := C.newFontDescriptor() // both of these are freed by C.newFont() + d.Family = C.CString(desc.Family) + d.Size = C.double(desc.Size) + d.Weight = C.uiDrawTextWeight(desc.Weight) + d.Italic = C.uiDrawTextItalic(desc.Italic) + d.SmallCaps = frombool(desc.SmallCaps) + d.Stretch = C.uiDrawTextStretch(desc.Stretch) +// d.Gravity = C.uiDrawTextGravity(desc.Gravity) + d.Gravity = C.uiDrawTextGravitySouth + return &Font{ + f: C.newFont(d), + } +} + +// Free destroys a Font. After calling Free the Font cannot be used. +func (f *Font) Free() { + C.uiDrawFreeTextFont(f.f) +} + +// Handle returns the OS font object that backs this Font. On OSs +// that use reference counting for font objects, Handle does not +// increment the reference count; you are sharing package ui's +// reference. +// +// On Windows this is a pointer to an IDWriteFont. +// +// On Unix systems this is a pointer to a PangoFont. +// +// On OS X this is a CTFontRef. +func (f *Font) Handle() uintptr { + return uintptr(C.uiDrawTextFontHandle(f.f)) +} + +// Describe returns the FontDescriptor that most closely matches +// this Font. +// TODO guarantees about idempotency +func (f *Font) Describe() *FontDescriptor { + panic("TODO unimplemented") +} + // 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 +// The block of text to lay out and the default font that is used if no +// font attributes are applied to a given character 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). @@ -662,19 +716,10 @@ type TextLayout struct { } // NewTextLayout creates a new TextLayout. -func NewTextLayout(text string, initialStyle *InitialTextStyle) *TextLayout { +func NewTextLayout(text string, defaultFont *Font) *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) + ctext := C.CString(text) // freed by C.newTextLayout() + l.l = C.newTextLayout(ctext, defaultFont.f) return l } |