Allow dialogues to be hidden or shown

To do this, MENU and SUBMENU are split into two types (at last), and
a Widget type is introduced. This should allow lots of code to be
removed at some point.

internal/ui/value.go

@@ -0,0 +1,119 @@
+package ui
+
+import (
+	"fmt"
+	"strconv"
+)
+
+func (d *Driver) realId(id string) string {
+	return fmt.Sprintf("%v:%v", d.menu.Name, id)
+}
+
+func (d *Driver) Value(id string, into *string) error {
+	for _, valueable := range d.valueables() {
+		if valueable.id() == d.realId(id) {
+			*into = valueable.value()
+			return nil
+		}
+	}
+
+	return fmt.Errorf("Couldn't find valueable widget %v:%v", d.menu.Name, id)
+}
+
+func (d *Driver) SetValue(id, value string) error {
+	for _, valueable := range d.valueables() {
+		if valueable.id() == d.realId(id) {
+			valueable.setValue(value)
+			return nil
+		}
+	}
+
+	return fmt.Errorf("Couldn't find valueable widget %v:%v", d.menu.Name, id)
+}
+
+func (d *Driver) ValueBool(id string, into *bool) error {
+	var vStr string
+	if err := d.Value(id, &vStr); err != nil {
+		return err
+	}
+
+	*into = vStr == "1"
+	return nil
+}
+
+func (d *Driver) SetValueBool(id string, value bool) error {
+	vStr := "0"
+	if value {
+		vStr = "1"
+	}
+
+	return d.SetValue(id, vStr)
+}
+
+func (d *Driver) SetFreeze(id string, value bool) error {
+	for _, freezable := range d.freezables() {
+		if freezable.id() == d.realId(id) {
+			freezable.setFreezeState(value)
+			return nil
+		}
+	}
+
+	return fmt.Errorf("Couldn't find clickable widget %v:%v", d.menu.Name, id)
+}
+
+func (d *Driver) OnClick(id string, f func()) error {
+	for _, clickable := range d.clickables() {
+		if clickable.id() == d.realId(id) {
+			clickable.onClick(f)
+			return nil
+		}
+	}
+
+	// We need to be able to wire up items inside dialogues too
+	for _, dialogue := range d.dialogues {
+		for _, clickable := range dialogue.clickables() {
+			if clickable.id() == d.realId(id) {
+				clickable.onClick(f)
+				return nil
+			}
+		}
+	}
+
+	return fmt.Errorf("Couldn't find clickable widget %v:%v", d.menu.Name, id)
+}
+
+// FIXME: HURK. Surely I'm missing something? steps is value:offset
+func (d *Driver) ConfigureSlider(id string, steps map[int]int) error {
+
+	for _, clickable := range d.clickables() {
+		if slider, ok := clickable.(*slider); ok && slider.id() == d.realId(id) {
+			slider.steps = steps
+
+			return nil
+		}
+	}
+
+	return fmt.Errorf("Couldn't find slider %v:%v", d.menu.Name, id)
+}
+
+func (d *Driver) ValueInt(id string, into *int) error {
+	var vStr string
+	if err := d.Value(id, &vStr); err != nil {
+		return err
+	}
+
+	value, err := strconv.Atoi(vStr)
+	if err != nil {
+		return err
+	}
+
+	*into = value
+
+	return nil
+}
+
+func (d *Driver) SetValueInt(id string, value int) error {
+	vStr := strconv.Itoa(value)
+
+	return d.SetValue(id, vStr)
+}