1 files changed, 167 insertions, 0 deletions
diff --git a/examples/drawtext.go b/examples/drawtext.go
new file mode 100644
index 0000000..a32b14b
--- /dev/null
+++ b/examples/drawtext.go
@@ -0,0 +1,167 @@
+// 19 august 2018
+
+// +build OMIT
+
+package main
+
+// TODO probably a bug in libui: changing the font away from skia leads to a crash
+
+import (
+	"github.com/andlabs/ui"
+)
+
+var (
+	fontButton *ui.FontButton
+	alignment *ui.Combobox
+
+	attrstr *ui.AttributedString
+)
+
+func appendWithAttributes(what string, attrs ...ui.Attribute) {
+	start := len(attrstr.String())
+	end := start + len(what)
+	attrstr.AppendUnattributed(what)
+	for _, a := range attrs {
+		attrstr.SetAttribute(a, start, end)
+	}
+}
+
+func makeAttributedString() {
+	attrstr = ui.NewAttributedString(
+		"Drawing strings with package ui is done with the ui.AttributedString and ui.DrawTextLayout objects.\n" +
+		"ui.AttributedString lets you have a variety of attributes: ")
+
+	appendWithAttributes("font family", ui.TextFamily("Courier New"))
+	attrstr.AppendUnattributed(", ")
+
+	appendWithAttributes("font size", ui.TextSize(18))
+	attrstr.AppendUnattributed(", ")
+
+	appendWithAttributes("font weight", ui.TextWeightBold)
+	attrstr.AppendUnattributed(", ")
+
+	appendWithAttributes("font italicness", ui.TextItalicItalic)
+	attrstr.AppendUnattributed(", ")
+
+	appendWithAttributes("font stretch", ui.TextStretchCondensed)
+	attrstr.AppendUnattributed(", ")
+
+	appendWithAttributes("text color", ui.TextColor{0.75, 0.25, 0.5, 0.75})
+	attrstr.AppendUnattributed(", ")
+
+	appendWithAttributes("text background color", ui.TextBackground{0.5, 0.5, 0.25, 0.5})
+	attrstr.AppendUnattributed(", ")
+
+	appendWithAttributes("underline style", ui.UnderlineSingle)
+	attrstr.AppendUnattributed(", ")
+
+	attrstr.AppendUnattributed("and ")
+	appendWithAttributes("underline color",
+		ui.UnderlineDouble,
+		ui.UnderlineColorCustom{1.0, 0.0, 0.5, 1.0})
+	attrstr.AppendUnattributed(". ")
+
+	attrstr.AppendUnattributed("Furthermore, there are attributes allowing for ")
+	appendWithAttributes("special underlines for indicating spelling errors",
+		ui.UnderlineSuggestion,
+		ui.UnderlineColorSpelling)
+	attrstr.AppendUnattributed(" (and other types of errors) ")
+
+	attrstr.AppendUnattributed("and control over OpenType features such as ligatures (for instance, ")
+	appendWithAttributes("afford", ui.OpenTypeFeatures{
+		ui.ToOpenTypeTag('l', 'i', 'g', 'a'):		0,
+	})
+	attrstr.AppendUnattributed(" vs. ")
+	appendWithAttributes("afford", ui.OpenTypeFeatures{
+		ui.ToOpenTypeTag('l', 'i', 'g', 'a'):		1,
+	})
+	attrstr.AppendUnattributed(").\n")
+
+	attrstr.AppendUnattributed("Use the controls opposite to the text to control properties of the text.")
+}
+
+type areaHandler struct{}
+
+func (areaHandler) Draw(a *ui.Area, p *ui.AreaDrawParams) {
+	tl := ui.DrawNewTextLayout(&ui.DrawTextLayoutParams{
+		String:		attrstr,
+		DefaultFont:	fontButton.Font(),
+		Width:		p.AreaWidth,
+		Align:		ui.DrawTextAlign(alignment.Selected()),
+	})
+	defer tl.Free()
+	p.Context.Text(tl, 0, 0)
+}
+
+func (areaHandler) MouseEvent(a *ui.Area, me *ui.AreaMouseEvent) {
+	// do nothing
+}
+
+func (areaHandler) MouseCrossed(a *ui.Area, left bool) {
+	// do nothing
+}
+
+func (areaHandler) DragBroken(a *ui.Area) {
+	// do nothing
+}
+
+func (areaHandler) KeyEvent(a *ui.Area, ke *ui.AreaKeyEvent) (handled bool) {
+	// reject all keys
+	return false
+}
+
+func setupUI() {
+	makeAttributedString()
+
+	mainwin := ui.NewWindow("libui Text-Drawing Example", 640, 480, true)
+	mainwin.SetMargined(true)
+	mainwin.OnClosing(func(*ui.Window) bool {
+		mainwin.Destroy()
+		ui.Quit()
+		return false
+	})
+	ui.OnShouldQuit(func() bool {
+		mainwin.Destroy()
+		return true
+	})
+
+	hbox := ui.NewHorizontalBox()
+	hbox.SetPadded(true)
+	mainwin.SetChild(hbox)
+
+	vbox := ui.NewVerticalBox()
+	vbox.SetPadded(true)
+	hbox.Append(vbox, false)
+
+	area := ui.NewArea(areaHandler{})
+
+	fontButton = ui.NewFontButton()
+	fontButton.OnChanged(func(*ui.FontButton) {
+		area.QueueRedrawAll()
+	})
+	vbox.Append(fontButton, false)
+
+	form := ui.NewForm()
+	form.SetPadded(true)
+	// TODO on OS X if this is set to 1 then the window can't resize; does the form not have the concept of stretchy trailing space?
+	vbox.Append(form, false)
+
+	alignment = ui.NewCombobox()
+	// note that the items match with the values of the uiDrawTextAlign values
+	alignment.Append("Left")
+	alignment.Append("Center")
+	alignment.Append("Right")
+	alignment.SetSelected(0)		// start with left alignment
+	alignment.OnSelected(func(*ui.Combobox) {
+		area.QueueRedrawAll()
+	})
+	form.Append("Alignment", alignment, false)
+
+	hbox.Append(area, true)
+
+	mainwin.Show()
+}
+
+func main() {
+	ui.Main(setupUI)
+}