diff options
| -rw-r--r-- | README.md | 82 |
1 files changed, 36 insertions, 46 deletions
@@ -81,55 +81,46 @@ Yes, `faiface/gui` uses CPU for drawing. You won't make AAA games with it, but t 3. No need to organize the API around a GPU library, like OpenGL. 4. Use all the good packages, like [`"image"`](https://golang.org/pkg/image/), [`"image/draw"`](https://golang.org/pkg/image/draw/), [`"golang.org/x/image/font"`](https://godoc.org/golang.org/x/image/font) for fonts, or [`"github.com/fogleman/gg"`](https://godoc.org/github.com/fogleman/gg) for shapes. -What is an [`Event`](https://godoc.org/github.com/faiface/gui#Event)? It's a `string`: +What is an [`Event`](https://godoc.org/github.com/faiface/gui#Event)? It's an interface: ```go -type Event string +type Event interface { + String() string +} ``` -Examples of `Event` strings are: `"wi/close"`, `"mo/move/104/320"`, `"kb/type/71"` (where `"wi"`, `"mo"`, and `"kb"` stand for _window_, _mouse_, and _keyboard_, respectively). A nice consequence of this form is that we can pattern match on it: +This purpose of this interface is to hold different kinds of events and be able to discriminate among them using a type switch. + +Examples of concrete `Event` types strings are: [`gui.Resize`](https://godoc.org/github.com/faiface/gui#Resize), [`win.WiClose`](https://godoc.org/github.com/faiface/gui/win#WiClose), [`win.MoDown`](https://godoc.org/github.com/faiface/gui/win#MoDown), [`win.KbType`](https://godoc.org/github.com/faiface/gui/win#KbType) (where `Wi`, `Mo`, and `Kb` stand for _window_, _mouse_, and _keyboard_, respectively). When we have an `Event`, we can type switch on it like this: ```go -switch { -case event.Matches("resize/%d/%d/%d/%d", &x0, &y0, &x1, &y1): - // environment resized to (x0, y0, x1, y1) -case event.Matches("wi/close"): +switch event := event.(type) { +case gui.Resize: + // environment resized to event.Rectangle +case win.WiClose: // window closed -case event.Matches("mo/move/%d/%d", &x, &y): - // mouse moved to (x, y) -case event.Matches("mo/down/%d/%d/%s", &x, &y, &btn): - // mouse button pressed on (x, y) -case event.Matches("mo/up/%d/%d/%s", &x, &y, &btn): - // mouse button released on (x, y) -case event.Matches("mo/scroll/%d/%d", &x, &y): - // mouse scrolled by (x, y) -case event.Matches("kb/type/%d", &r): - // rune r typed on the keyboard (encoded as a number in the event string) -case event.Matches("kb/down/%s", &key): - // keyboard key pressed on the keyboard -case event.Matches("kb/up/%s", &key): - // keyboard key released on the keyboard -case event.Matches("kb/repeat/%s", &key): - // keyboard key repeated on the keyboard (happens when held) +case win.MoMove: + // mouse moved to event.Point +case win.MoDown: + // mouse button event.Button pressed on event.Point +case win.MoUp: + // mouse button event.Button released on event.Point +case win.MoScroll: + // mouse scrolled by event.Point +case win.KbType: + // rune event.Rune typed on the keyboard +case win.KbDown: + // keyboard key event.Key pressed on the keyboard +case win.KbUp: + // keyboard key event.Key released on the keyboard +case win.KbRepeat: + // keyboard key event.Key repeated on the keyboard (happens when held) } ``` -This shows all the possible events that a window can produce. You can find a little more info (especially on the keys) [here in GoDoc](https://godoc.org/github.com/faiface/gui/win#Win). - -The `"resize"` event is not prefixed with `"wi/"`, because it's not specific to windows. It is also guaranteed to be the first event produced by any `Env`. - -You can also match only specific buttons/keys, or ignore them: +This shows all the possible events that a window can produce. -```go -switch { -case event.Matches("mo/down/%d/%d/left", &x, &y): - // only matches when the left button is pressed -case event.Matches("kb/down/up"): - // matches the UP key on the keyboard -case event.Matches("mo/down/%d/%d", &x, &y): - // matches mouse press with any button -} -``` +The [`gui.Resize`](https://godoc.org/github.com/faiface/gui#Resize) event is not from the package [`win`](https://godoc.org/github.com/faiface/gui/win) because it's not window specific. In fact, every `Env` guarantees to produce `gui.Resize` as its first event. How do we create a window? With the [`"github.com/faiface/gui/win"`](https://godoc.org/github.com/faiface/gui/win) package: @@ -180,8 +171,8 @@ func run() { } for event := range w.Events() { - switch { - case event.Matches("wi/close"): + switch event.(type) { + case win.WiClose: close(w.Draw()) } } @@ -252,10 +243,9 @@ func Blinker(env gui.Env, r image.Rectangle) { env.Draw() <- redraw(true) for event := range env.Events() { - var x, y int - switch { - case event.Matches("mo/down/%d/%d", &x, &y): - if image.Pt(x, y).In(r) { + switch event := event.(type) { + case win.MoDown: + if event.Point.In(r) { // user clicked on the rectangle // we blink 3 times for i := 0; i < 3; i++ { @@ -287,8 +277,8 @@ func run() { // we use the master env now, w is used by the mux for event := range env.Events() { - switch { - case event.Matches("wi/close"): + switch event.(type) { + case win.WiClose: close(env.Draw()) } } |