xlib demo

Author: evmar

example/window.go

@@ -0,0 +1,48 @@
+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"github.com/martine/gocairo/cairo"
+	"github.com/martine/gocairo/xlib"
+)
+
+type callbacks struct{}
+
+func (c *callbacks) Draw(cr *cairo.Context, surf *cairo.XlibSurface) {
+	w, h := surf.GetWidth(), surf.GetHeight()
+	grid := 32
+
+	cr.SetSourceRGB(0, 0, 0)
+	cr.Paint()
+
+	cr.SetAntialias(cairo.AntialiasBest)
+	// Offset by 0.5 to get pixel-aligned lines.
+	cr.Translate(0.5, 0.5)
+	cr.SetSourceRGB(1, 0, 0)
+	for x := 0; x <= w; x += grid {
+		for y := 0; y <= h; y += grid {
+			ofs := x/grid + y/grid
+			cr.Rectangle(float64(x+ofs), float64(y+ofs),
+				float64(grid-(2*ofs)), float64(grid-(2*ofs)))
+			cr.Fill()
+		}
+	}
+}
+
+func main() {
+	var callbacks callbacks
+	xlib.XMain(&callbacks)
+}

xlib/xeventtype_string.go

@@ -0,0 +1,17 @@
+// generated by stringer -type=XEventType; DO NOT EDIT
+
+package xlib
+
+import "fmt"
+
+const _XEventType_name = "KeyPressKeyReleaseButtonPressButtonReleaseMotionNotifyEnterNotifyLeaveNotifyFocusInFocusOutKeymapNotifyExposeGraphicsExposeNoExposeVisibilityNotifyCreateNotifyDestroyNotifyUnmapNotifyMapNotifyMapRequestReparentNotifyConfigureNotifyConfigureRequestGravityNotifyResizeRequestCirculateNotifyCirculateRequestPropertyNotifySelectionClearSelectionRequestSelectionNotifyColormapNotifyClientMessageMappingNotifyGenericEvent"
+
+var _XEventType_index = [...]uint16{0, 8, 18, 29, 42, 54, 65, 76, 83, 91, 103, 109, 123, 131, 147, 159, 172, 183, 192, 202, 216, 231, 247, 260, 273, 288, 304, 318, 332, 348, 363, 377, 390, 403, 415}
+
+func (i XEventType) String() string {
+	i -= 2
+	if i < 0 || i+1 >= XEventType(len(_XEventType_index)) {
+		return fmt.Sprintf("XEventType(%d)", i+2)
+	}
+	return _XEventType_name[_XEventType_index[i]:_XEventType_index[i+1]]
+}

xlib/xlib.go

@@ -0,0 +1,112 @@
+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package xlib
+
+/*
+#cgo pkg-config: x11
+#include <X11/Xlib.h>
+*/
+import "C"
+
+import (
+	"unsafe"
+
+	"github.com/martine/gocairo/cairo"
+)
+
+type Callbacks interface {
+	Draw(*cairo.Context, *cairo.XlibSurface)
+}
+
+type Window struct {
+	dpy *C.Display
+	xw  C.Window
+}
+
+// Note that stringer doesn't work in the presence of C types.  I worked
+// around this by just commenting out all the code except for XEventType
+// when running "go generate".
+
+//go:generate stringer -type=XEventType
+type XEventType int
+
+const (
+	KeyPress         XEventType = 2
+	KeyRelease       XEventType = 3
+	ButtonPress      XEventType = 4
+	ButtonRelease    XEventType = 5
+	MotionNotify     XEventType = 6
+	EnterNotify      XEventType = 7
+	LeaveNotify      XEventType = 8
+	FocusIn          XEventType = 9
+	FocusOut         XEventType = 10
+	KeymapNotify     XEventType = 11
+	Expose           XEventType = 12
+	GraphicsExpose   XEventType = 13
+	NoExpose         XEventType = 14
+	VisibilityNotify XEventType = 15
+	CreateNotify     XEventType = 16
+	DestroyNotify    XEventType = 17
+	UnmapNotify      XEventType = 18
+	MapNotify        XEventType = 19
+	MapRequest       XEventType = 20
+	ReparentNotify   XEventType = 21
+	ConfigureNotify  XEventType = 22
+	ConfigureRequest XEventType = 23
+	GravityNotify    XEventType = 24
+	ResizeRequest    XEventType = 25
+	CirculateNotify  XEventType = 26
+	CirculateRequest XEventType = 27
+	PropertyNotify   XEventType = 28
+	SelectionClear   XEventType = 29
+	SelectionRequest XEventType = 30
+	SelectionNotify  XEventType = 31
+	ColormapNotify   XEventType = 32
+	ClientMessage    XEventType = 33
+	MappingNotify    XEventType = 34
+	GenericEvent     XEventType = 35
+)
+
+func XMain(callbacks Callbacks) {
+	dpy := C.XOpenDisplay(nil)
+
+	w := C.XCreateSimpleWindow(dpy, C.XDefaultRootWindow(dpy),
+		0, 0, 600, 400,
+		0, 0, 0)
+	C.XSelectInput(dpy, w, C.StructureNotifyMask|C.SubstructureNotifyMask|C.ExposureMask)
+	C.XMapWindow(dpy, w)
+
+	win := Window{dpy: dpy, xw: w}
+	visual := C.XDefaultVisual(dpy, 0)
+
+	surf := cairo.XlibSurfaceCreate(unsafe.Pointer(dpy), uint64(win.xw), unsafe.Pointer(visual), 10, 10)
+
+	for {
+		var e C.XEvent
+		C.XNextEvent(dpy, &e)
+		typ := XEventType(*(*C.int)(unsafe.Pointer(&e)))
+		// log.Printf("X event: %s", typ)
+		switch typ {
+		case C.ConfigureNotify:
+			e := (*C.XConfigureEvent)(unsafe.Pointer(&e))
+			surf.SetSize(int(e.width), int(e.height))
+		case C.Expose:
+			cr := cairo.Create(surf.Surface)
+			callbacks.Draw(cr, surf)
+		default:
+			// log.Printf("unknown X event %s", typ)
+		}
+	}
+}