path: root/pkg/gui/gui.go

package gui

import (

	// "io"
	// "io/ioutil"

	"errors"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
	"strings"
	"time"

	// "strings"

	"github.com/Sirupsen/logrus"
	"github.com/golang-collections/collections/stack"
	"github.com/jesseduffield/gocui"
	"github.com/jesseduffield/lazygit/pkg/commands"
	"github.com/jesseduffield/lazygit/pkg/config"
	"github.com/jesseduffield/lazygit/pkg/i18n"
)

// OverlappingEdges determines if panel edges overlap
var OverlappingEdges = false

// SentinelErrors are the errors that have special meaning and need to be checked
// by calling functions. The less of these, the better
type SentinelErrors struct {
	ErrSubProcess error
	ErrNoFiles    error
}

// GenerateSentinelErrors makes the sentinel errors for the gui. We're defining it here
// because we can't do package-scoped errors with localization, and also because
// it seems like package-scoped variables are bad in general
// https://dave.cheney.net/2017/06/11/go-without-package-scoped-variables
// In the future it would be good to implement some of the recommendations of
// that article. For now, if we don't need an error to be a sentinel, we will just
// define it inline. This has implications for error messages that pop up everywhere
// in that we'll be duplicating the default values. We may need to look at
// having a default localisation bundle defined, and just using keys-only when
// localising things in the code.
func (gui *Gui) GenerateSentinelErrors() {
	gui.Errors = SentinelErrors{
		ErrSubProcess: errors.New(gui.Tr.SLocalize("RunningSubprocess")),
		ErrNoFiles:    errors.New(gui.Tr.SLocalize("NoChangedFiles")),
	}
}

// Teml is short for template used to make the required map[string]interface{} shorter when using gui.Tr.SLocalize and gui.Tr.TemplateLocalize
type Teml i18n.Teml

// Gui wraps the gocui Gui object which handles rendering and events
type Gui struct {
	g          *gocui.Gui
	Log        *logrus.Logger
	GitCommand *commands.GitCommand
	OSCommand  *commands.OSCommand
	SubProcess *exec.Cmd
	State      guiState
	Config     config.AppConfigurer
	Tr         *i18n.Localizer
	Errors     SentinelErrors
}

type guiState struct {
	Files             []commands.File
	Branches          []commands.Branch
	Commits           []commands.Commit
	StashEntries      []commands.StashEntry
	PreviousView      string
	HasMergeConflicts bool
	ConflictIndex     int
	ConflictTop       bool
	Conflicts         []commands.Conflict
	EditHistory       *stack.Stack
	Platform          commands.Platform
}

// NewGui builds a new gui handler
func NewGui(log *logrus.Logger, gitCommand *commands.GitCommand, oSCommand *commands.OSCommand, tr *i18n.Localizer, config config.AppConfigurer) (*Gui, error) {
	initialState := guiState{
		Files:         make([]commands.File, 0),
		PreviousView:  "files",
		Commits:       make([]commands.Commit, 0),
		StashEntries:  make([]commands.StashEntry, 0),
		ConflictIndex: 0,
		ConflictTop:   true,
		Conflicts:     make([]commands.Conflict, 0),
		EditHistory:   stack.New(),
		Platform:      *oSCommand.Platform,
	}

	gui := &Gui{
		Log:        log,
		GitCommand: gitCommand,
		OSCommand:  oSCommand,
		State:      initialState,
		Config:     config,
		Tr:         tr,
	}

	gui.GenerateSentinelErrors()

	return gui, nil
}

func (gui *Gui) scrollUpMain(g *gocui.Gui, v *gocui.View) error {
	mainView, _ := g.View("main")
	ox, oy := mainView.Origin()
	if oy >= 1 {
		return mainView.SetOrigin(ox, oy-gui.Config.GetUserConfig().GetInt("gui.scrollHeight"))
	}
	return nil
}

func (gui *Gui) scrollDownMain(g *gocui.Gui, v *gocui.View) error {
	mainView, _ := g.View("main")
	ox, oy := mainView.Origin()
	if oy < len(mainView.BufferLines()) {
		return mainView.SetOrigin(ox, oy+gui.Config.GetUserConfig().GetInt("gui.scrollHeight"))
	}
	return nil
}

func (gui *Gui) handleRefresh(g *gocui.Gui, v *gocui.View) error {
	return gui.refreshSidePanels(g)
}

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

// layout is called for every screen re-render e.g. when the screen is resized
func (gui *Gui) layout(g *gocui.Gui) error {
	g.Highlight = true
	width, height := g.Size()
	version := gui.Config.GetVersion()
	leftSideWidth := width / 3
	statusFilesBoundary := 2
	filesBranchesBoundary := 2 * height / 5   // height - 20
	commitsBranchesBoundary := 3 * height / 5 // height - 10
	commitsStashBoundary := height - 5        // height - 5
	optionsVersionBoundary := width - max(len(version), 1)
	minimumHeight := 16
	minimumWidth := 10

	panelSpacing := 1
	if OverlappingEdges {
		panelSpacing = 0
	}

	if height < minimumHeight || width < minimumWidth {
		v, err := g.SetView("limit", 0, 0, max(width-1, 2), max(height-1, 2), 0)
		if err != nil {
			if err != gocui.ErrUnknownView {
				return err
			}
			v.Title = gui.Tr.SLocalize("NotEnoughSpace")
			v.Wrap = true
		}
		return nil
	}

	g.DeleteView("limit")

	optionsTop := height - 2
	// hiding options if there's not enough space
	if height < 30 {
		optionsTop = height - 1
	}

	v, err := g.SetView("main", leftSideWidth+panelSpacing, 0, width-1, optionsTop, gocui.LEFT)
	if err != nil {
		if err != gocui.ErrUnknownView {
			return err
		}
		v.Title = gui.Tr.SLocalize("DiffTitle")
		v.Wrap = true
		v.FgColor = gocui.ColorWhite
	}

	if v, err := g.SetView("status", 0, 0, leftSideWidth, statusFilesBoundary, gocui.BOTTOM|gocui.RIGHT); err != nil {
		if err != gocui.ErrUnknownView {
			return err
		}
		v.Title = gui.Tr.SLocalize("StatusTitle")
		v.FgColor = gocui.ColorWhite
	}

	filesView, err := g.SetView("files", 0, statusFilesBoundary+panelSpacing, leftSideWidth, filesBranchesBoundary, gocui.TOP|gocui.BOTTOM)
	if err != nil {
		if err != gocui.ErrUnknownView {
			return err
		}
		filesView.Highlight = true
		filesView.Title = gui.Tr.SLocalize("FilesTitle")
		v.FgColor = gocui.ColorWhite
	}

	if v, err := g.SetView("branches", 0, filesBranchesBoundary+panelSpacing, leftSideWidth, commitsBranchesBoundary, gocui.TOP|gocui.BOTTOM); err != nil {
		if err != gocui.ErrUnknownView {
			return err
		}
		v.Title