refactor contexts code

1 files changed, 231 insertions, 0 deletions

diff --git a/pkg/gui/context/list_context_trait.go b/pkg/gui/context/list_context_trait.go
new file mode 100644
index 000000000..776056fad
--- /dev/null
+++ b/pkg/gui/context/list_context_trait.go
@@ -0,0 +1,231 @@
+package context
+
+import (
+	"fmt"
+
+	"github.com/jesseduffield/gocui"
+	"github.com/jesseduffield/lazygit/pkg/config"
+	"github.com/jesseduffield/lazygit/pkg/gui/types"
+	"github.com/jesseduffield/lazygit/pkg/utils"
+)
+
+type Thing interface {
+	// the boolean here tells us whether the item is nil. This is needed because you can't work it out on the calling end once the pointer is wrapped in an interface (unless you want to use reflection)
+	GetSelectedItem() (types.ListItem, bool)
+}
+
+type ListContextTrait struct {
+	base      types.IBaseContext
+	thing     Thing
+	listTrait *ListTrait
+	viewTrait *ViewTrait
+
+	takeFocus func() error
+
+	GetDisplayStrings func(startIdx int, length int) [][]string
+	OnFocus           func(...types.OnFocusOpts) error
+	OnRenderToMain    func(...types.OnFocusOpts) error
+	OnFocusLost       func() error
+
+	// if this is true, we'll call GetDisplayStrings for just the visible part of the
+	// view and re-render that. This is useful when you need to render different
+	// content based on the selection (e.g. for showing the selected commit)
+	RenderSelection bool
+
+	c *types.ControllerCommon
+}
+
+func (self *ListContextTrait) GetPanelState() types.IListPanelState {
+	return self.listTrait
+}
+
+func (self *ListContextTrait) FocusLine() {
+	// we need a way of knowing whether we've rendered to the view yet.
+	self.viewTrait.FocusPoint(self.listTrait.GetSelectedLineIdx())
+	if self.RenderSelection {
+		min, max := self.viewTrait.ViewPortYBounds()
+		displayStrings := self.GetDisplayStrings(min, max)
+		content := utils.RenderDisplayStrings(displayStrings)
+		self.viewTrait.SetViewPortContent(content)
+	}
+	self.viewTrait.SetFooter(formatListFooter(self.listTrait.GetSelectedLineIdx(), self.listTrait.GetItemsLength()))
+}
+
+func formatListFooter(selectedLineIdx int, length int) string {
+	return fmt.Sprintf("%d of %d", selectedLineIdx+1, length)
+}
+
+func (self *ListContextTrait) GetSelectedItemId() string {
+	item, ok := self.thing.GetSelectedItem()
+
+	if !ok {
+		return ""
+	}
+
+	return item.ID()
+}
+
+// OnFocus assumes that the content of the context has already been rendered to the view. OnRender is the function which actually renders the content to the view
+func (self *ListContextTrait) HandleRender() error {
+	if self.GetDisplayStrings != nil {
+		self.listTrait.RefreshSelectedIdx()
+		content := utils.RenderDisplayStrings(self.GetDisplayStrings(0, self.listTrait.GetItemsLength()))
+		self.viewTrait.SetContent(content)
+		self.c.Render()
+	}
+
+	return nil
+}
+
+func (self *ListContextTrait) HandleFocusLost() error {
+	if self.OnFocusLost != nil {
+		return self.OnFocusLost()
+	}
+
+	self.viewTrait.SetOriginX(0)
+
+	return nil
+}
+
+func (self *ListContextTrait) HandleFocus(opts ...types.OnFocusOpts) error {
+	self.FocusLine()
+
+	if self.OnFocus != nil {
+		if err := self.OnFocus(opts...); err != nil {
+			return err
+		}
+	}
+
+	if self.OnRenderToMain != nil {
+		if err := self.OnRenderToMain(opts...); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (self *ListContextTrait) HandlePrevLine() error {
+	return self.handleLineChange(-1)
+}
+
+func (self *ListContextTrait) HandleNextLine() error {
+	return self.handleLineChange(1)
+}
+
+func (self *ListContextTrait) HandleScrollLeft() error {
+	return self.scroll(self.viewTrait.ScrollLeft)
+}
+
+func (self *ListContextTrait) HandleScrollRight() error {
+	return self.scroll(self.viewTrait.ScrollRight)
+}
+
+func (self *ListContextTrait) scroll(scrollFunc func()) error {
+	scrollFunc()
+
+	return self.HandleFocus()
+}
+
+func (self *ListContextTrait) handleLineChange(change int) error {
+	before := self.listTrait.GetSelectedLineIdx()
+	self.listTrait.MoveSelectedLine(change)
+	after := self.listTrait.GetSelectedLineIdx()
+
+	if before != after {
+		return self.HandleFocus()
+	}
+
+	return nil
+}
+
+func (self *ListContextTrait) HandlePrevPage() error {
+	return self.handleLineChange(-self.viewTrait.PageDelta())
+}
+
+func (self *ListContextTrait) HandleNextPage() error {
+	return self.handleLineChange(self.viewTrait.PageDelta())
+}
+
+func (self *ListContextTrait) HandleGotoTop() error {
+	return self.handleLineChange(-self.listTrait.GetItemsLength())
+}
+
+func (self *ListContextTrait) HandleGotoBottom() error {
+	return self.handleLineChange(self.listTrait.GetItemsLength())
+}
+
+func (self *ListContextTrait) HandleClick(onClick func() error) error {
+	prevSelectedLineIdx := self.listTrait.GetSelectedLineIdx()
+	// because we're handling a click, we need to determine the new line idx based
+	// on the view itself.
+	newSelectedLineIdx := self.viewTrait.SelectedLineIdx()
+
+	currentContextKey := self.c.CurrentContext().GetKey()
+	alreadyFocused := currentContextKey == self.base.GetKey()
+
+	// we need to focus the view
+	if !alreadyFocused {
+
+		if err := self.takeFocus(); err != nil {
+			return err
+		}
+	}
+
+	if newSelectedLineIdx > self.listTrait.GetItemsLength()-1 {
+		return nil
+	}
+
+	self.listTrait.SetSelectedLineIdx(newSelectedLineIdx)
+
+	if prevSelectedLineIdx == newSelectedLineIdx && alreadyFocused && onClick != nil {
+		return onClick()
+	}
+	return self.HandleFocus()
+}
+
+func (self *ListContextTrait) OnSearchSelect(selectedLineIdx int) error {
+	self.listTrait.SetSelectedLineIdx(selectedLineIdx)
+	return self.HandleFocus()
+}
+
+func (self *ListContextTrait) HandleRenderToMain() error {
+	if self.OnRenderToMain != nil {
+		return self.OnRenderToMain()
+	}
+
+	return nil
+}
+
+func (self *ListContextTrait) Keybindings(
+	getKey func(key string) interface{},
+	config config.KeybindingConfig,
+	guards types.KeybindingGuards,
+) []*types.Binding {
+	return []*types.Binding{
+		{Tag: "navigation", Key: getKey(config.Universal.PrevItemAlt), Modifier: gocui.ModNone, Handler: self.HandlePrevLine},
+		{Tag: "navigation", Key: getKey(config.Universal.PrevItem), Modifier: gocui.ModNone, Handler: self.HandlePrevLine},
+		{Tag: "navigation", Key: gocui.MouseWheelUp, Modifier: gocui.ModNone, Handler: self.HandlePrevLine},
+		{Tag: "navigation", Key: getKey(config.Universal.NextItemAlt), Modifier: gocui.ModNone, Handler: self.HandleNextLine},
+		{Tag: "navigation", Key: getKey(config.Universal.NextItem), Modifier: gocui.ModNone, Handler: self.HandleNextLine},
+		{Tag: "navigation", Key: getKey(config.Universal.PrevPage), Modifier: gocui.ModNone, Handler: self.HandlePrevPage, Description: self.c.Tr.LcPrevPage},
+		{Tag: "navigation", Key: getKey(config.Universal.NextPage), Modifier: gocui.ModNone, Handler: self.HandleNextPage, Description: self.c.Tr.LcNextPage},
+		{Tag: "navigation", Key: getKey(config.Universal.GotoTop), Modifier: gocui.ModNone, Handler: self.HandleGotoTop, Description: self.c.Tr.LcGotoTop},
+		{Key: gocui.MouseLeft, Modifier: gocui.ModNone, Handler: func() error { return self.HandleClick(nil) }},
+		{Tag: "navigation", Key: gocui.MouseWheelDown, Modifier: gocui.ModNone, Handler: self.HandleNextLine},
+		{Tag: "navigation", Key: getKey(config.Universal.ScrollLeft), Modifier: gocui.ModNone, Handler: self.HandleScrollLeft},
+		{Tag: "navigation", Key: getKey(config.Universal.ScrollRight), Modifier: gocui.ModNone, Handler: self.HandleScrollRight},
+		{
+			Key:         getKey(config.Universal.StartSearch),
+			Handler:     func() error { self.c.OpenSearch(); return nil },
+			Description: self.c.Tr.LcStartSearch,
+			Tag:         "navigation",
+		},
+		{
+			Key:         getKey(config.Universal.GotoBottom),
+			Description: self.c.Tr.LcGotoBottom,
+			Handler:     self.HandleGotoBottom,
+			Tag:         "navigation",
+		},
+	}
+}