Added a slider widget, with an implementation for WIN32. Implementation for GTK will need to follow. Small fixes to formatting of doc comments.

Author: rj

intinput.go

@@ -11,7 +11,7 @@ var (
 // IntInput describes a widget that users input or update a single integer value.
 // The model for the value is a int64.
 type IntInput struct {
-	Value       int64              // Values is the current string for the field
+	Value       int64              // Value is the current value for the field
 	Placeholder string             // Placeholder is a descriptive text that can be displayed when the field is empty
 	Disabled    bool               // Disabled is a flag indicating that the user cannot interact with this field
 	OnChange    func(value int64)  // OnChange will be called whenever the user changes the value for this field

label.go

@@ -20,7 +20,7 @@ func (*Label) Kind() *base.Kind {
 }
 
 // Mount creates a label control in the GUI.
-//  The newly created widget will be a child of the widget specified by parent.
+// The newly created widget will be a child of the widget specified by parent.
 func (w *Label) Mount(parent base.Control) (base.Element, error) {
 	// Forward to the platform-dependant code
 	return w.mount(parent)

label_windows.go

@@ -10,8 +10,7 @@ import (
 )
 
 var (
-	staticClassName     []uint16
-	oldStaticWindowProc uintptr
+	staticClassName []uint16
 )
 
 func init() {

mainwindow_windows.go

@@ -596,7 +596,16 @@ func windowWindowProc(hwnd win.HWND, msg uint32, wParam uintptr, lParam uintptr)
 		// Defer to the default window proc
 
 	case win.WM_HSCROLL:
-		windowGetPtr(hwnd).setScrollPos(win.SB_HORZ, wParam)
+		if lParam == 0 {
+			// Message was sent by a standard scroll bar.  Need to adjust the
+			// scroll position for the window.
+			windowGetPtr(hwnd).setScrollPos(win.SB_HORZ, wParam)
+		} else {
+			// Message was sent by a child window.  As for all other controls
+			// that notify the parent, resend to the child with the expectation
+			// that the child has been subclassed.
+			win.SendMessage(win.HWND(lParam), win.WM_HSCROLL, wParam, 0)
+		}
 		return 0
 
 	case win.WM_VSCROLL:

progress.go

@@ -14,8 +14,8 @@ var (
 // If both Min and Max are zero, then Max will be updated to 100.  Other cases
 // where Min == Max are not allowed.
 type Progress struct {
-	Value    int
-	Min, Max int
+	Value    int // Value is the current value to be displayed
+	Min, Max int // Min and Max set the range of Value
 }
 
 // Kind returns the concrete type for use in the Widget interface.

slider.go

@@ -0,0 +1,59 @@
+package goey
+
+import (
+	"bitbucket.org/rj/goey/base"
+)
+
+var (
+	sliderKind = base.NewKind("bitbucket.org/rj/goey.Slider")
+)
+
+// Slider describes a widget that users input or update a single real value.
+// The model for the value is a float64.
+//
+// If both Min and Max are zero, then Max will be updated to 100.  Other cases
+// where Min == Max are not allowed.
+type Slider struct {
+	Value    float64       // Value is the current value for the field
+	Disabled bool          // Disabled is a flag indicating that the user cannot interact with this field
+	Min, Max float64       // Min and Max set the range of Value
+	OnChange func(float64) // OnChange will be called whenever the user changes the value for this field
+	OnFocus  func()        // OnFocus will be called whenever the slider receives the keyboard focus.
+	OnBlur   func()        // OnBlur will be called whenever the slider loses the keyboard focus.
+}
+
+// Kind returns the concrete type for use in the Widget interface.
+// Users should not need to use this method directly.
+func (*Slider) Kind() *base.Kind {
+	return &sliderKind
+}
+
+// Mount creates a slider control in the GUI.
+// The newly created widget will be a child of the widget specified by parent.
+func (w *Slider) Mount(parent base.Control) (base.Element, error) {
+	// Fill in default values for the range.
+	w.UpdateRange()
+
+	// Forward to the platform-dependant code
+	return w.mount(parent)
+}
+
+// UpdateRange sets a default range when Min and Max are uninitialized.
+func (w *Slider) UpdateRange() {
+	if w.Min == 0 && w.Max == 0 {
+		w.Max = 100
+	}
+}
+
+func (*sliderElement) Kind() *base.Kind {
+	return &sliderKind
+}
+
+func (w *sliderElement) UpdateProps(data base.Widget) error {
+	slider := data.(*Slider)
+
+	// Fill in default values for the range.
+	slider.UpdateRange()
+	// Forward to the platform-dependant code
+	return w.updateProps(slider)
+}

slider_test.go

@@ -0,0 +1,103 @@
+package goey
+
+import (
+	"bitbucket.org/rj/goey/base"
+	"fmt"
+	"strconv"
+	"testing"
+)
+
+func ExampleSlider() {
+	value := 0.0
+
+	// In a full application, this variable would be updated to point to
+	// the main window for the application.
+	var mainWindow *Window
+	// These functions are used to update the GUI.  See below
+	var update func()
+	var render func() base.Widget
+
+	// Update function
+	update = func() {
+		err := mainWindow.SetChild(render())
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	// Render function generates a tree of Widgets to describe the desired
+	// state of the GUI.
+	render = func() base.Widget {
+		// Prep - text for the button
+		text := "Value: " + strconv.FormatFloat(value, 'f', 1, 64)
+		// The GUI contains a single widget, this button.
+		return &VBox{
+			AlignMain:  MainCenter,
+			AlignCross: CrossCenter,
+			Children: []base.Widget{
+				&Label{Text: text},
+				&Slider{
+					Value: value,
+					OnChange: func(v float64) {
+						value = v
+						update()
+					},
+				},
+			},
+		}
+	}
+
+	err := Run(func() error {
+		w, err := NewWindow("Slider", render())
+		if err != nil {
+			return err
+		}
+
+		mainWindow = w
+		return nil
+	})
+	if err != nil {
+		fmt.Println("Error:", err)
+	} else {
+		fmt.Println("OK")
+	}
+
+	// Output:
+	// OK
+}
+
+func TestSliderCreate(t *testing.T) {
+	testingRenderWidgets(t,
+		&Slider{Value: 50},
+		&Slider{Value: 50, Disabled: true},
+		&Slider{Value: 500, Max: 1000},
+	)
+}
+
+func TestSliderClose(t *testing.T) {
+	testingCloseWidgets(t,
+		&Slider{Value: 50},
+		&Slider{Value: 50, Disabled: true},
+		&Slider{Value: 500, Max: 1000},
+	)
+}
+
+func TestSliderFocus(t *testing.T) {
+	testingCheckFocusAndBlur(t,
+		&Slider{Value: 50},
+		&Slider{Value: 50},
+		&Slider{Value: 500, Max: 1000},
+	)
+}
+
+func TestSliderUpdate(t *testing.T) {
+	testingUpdateWidgets(t, []base.Widget{
+		&Slider{Value: 50},
+		&Slider{Value: 50, Disabled: true},
+		&Slider{Value: 500, Max: 1000},
+	}, []base.Widget{
+		&Slider{Value: 50},
+		&Slider{Value: 50, Min: 10, Max: 60},
+		&Slider{Value: 500, Max: 1000, Disabled: true},
+	})
+}