fix up boxes to actually work when moved around the screen

ui/mock.go

@@ -0,0 +1,116 @@
+package ui
+
+import (
+	"fmt"
+
+	"github.com/gdamore/tcell"
+)
+
+type coord struct {
+	x, y int
+}
+
+type MockScreen struct {
+	x, y, h, w int
+	content    map[coord]rune
+}
+
+func (m *MockScreen) Init() error {
+	m.content = map[coord]rune{}
+	return nil
+}
+
+func (m *MockScreen) Fini() {}
+
+func (m *MockScreen) Clear() {
+	m.content = map[coord]rune{}
+}
+
+func (m *MockScreen) Fill(rune, tcell.Style) {}
+
+func (m *MockScreen) SetCell(x int, y int, style tcell.Style, ch ...rune) {}
+
+func (m *MockScreen) GetContent(x, y int) (mainc rune, combc []rune, style tcell.Style, width int) {
+	return m.content[coord{x, y}], nil, tcell.StyleDefault, 1
+}
+
+func (m *MockScreen) SetContent(x int, y int, mainc rune, combc []rune, style tcell.Style) {
+	m.content[coord{x, y}] = mainc
+}
+
+func (m *MockScreen) SetStyle(style tcell.Style) {}
+
+func (m *MockScreen) ShowCursor(x int, y int) {}
+
+func (m *MockScreen) HideCursor() {}
+
+func (m *MockScreen) Size() (int, int) {
+	return m.h, m.w
+}
+
+func (m *MockScreen) PollEvent() tcell.Event {
+	return tcell.NewEventError(fmt.Errorf("mock error"))
+}
+
+func (m *MockScreen) PostEvent(ev tcell.Event) error {
+	return nil
+}
+
+func (m *MockScreen) PostEventWait(ev tcell.Event) {}
+
+func (m *MockScreen) EnableMouse() {}
+
+func (m *MockScreen) DisableMouse() {}
+
+func (m *MockScreen) HasMouse() bool {
+	return false
+}
+
+func (m *MockScreen) Colors() int {
+	return 0
+}
+
+func (m *MockScreen) Show() {}
+
+func (m *MockScreen) Sync() {}
+
+func (m *MockScreen) CharacterSet() string {
+	return "UTF-8"
+}
+
+func (m *MockScreen) RegisterRuneFallback(r rune, subst string) {}
+
+func (m *MockScreen) UnregisterRuneFallback(r rune) {}
+
+func (m *MockScreen) CanDisplay(r rune, checkFallbacks bool) bool {
+	return true
+}
+
+func (m *MockScreen) Resize(x, y, h, w int) {
+	m.x, m.y, m.h, m.w = x, y, h, w
+}
+
+func (m *MockScreen) HasKey(tcell.Key) bool {
+	return true
+}
+
+func (m *MockScreen) Beep() error {
+	return nil
+}
+
+func (m *MockScreen) DumpContents() string {
+	var res string
+	for i := m.y; i < m.h; i++ {
+		str := []rune{}
+		for j := m.x; j < m.w; j++ {
+			r, ok := m.content[coord{x: j, y: i}]
+			if ok {
+				str = append(str, r)
+			} else {
+				str = append(str, ' ')
+			}
+		}
+		res = res + string(str) + "\n"
+	}
+	return res
+}