supporing custom pagers step 1

11 files changed, 233 insertions, 30 deletions

diff --git a/pkg/commands/git.go b/pkg/commands/git.go
index 1e4f1e990..e41648ed3 100644
--- a/pkg/commands/git.go
+++ b/pkg/commands/git.go
@@ -177,7 +177,7 @@ func stashEntryFromLine(line string, index int) *StashEntry {
 
 // GetStashEntryDiff stash diff
 func (c *GitCommand) ShowStashEntryCmdStr(index int) string {
-	return fmt.Sprintf("git stash show -p --color stash@{%d}", index)
+	return fmt.Sprintf("git stash show -p --color=%s stash@{%d}", c.colorArg(), index)
 }
 
 // GetStatusFiles git status files
@@ -558,11 +558,11 @@ func (c *GitCommand) Ignore(filename string) error {
 }
 
 func (c *GitCommand) ShowCmdStr(sha string) string {
-	return fmt.Sprintf("git show --color --no-renames --stat -p %s", sha)
+	return fmt.Sprintf("git show --color=%s --no-renames --stat -p %s", c.colorArg(), sha)
 }
 
 func (c *GitCommand) GetBranchGraphCmdStr(branchName string) string {
-	return fmt.Sprintf("git log --graph --color --abbrev-commit --decorate --date=relative --pretty=medium %s", branchName)
+	return fmt.Sprintf("git log --graph --color=always --abbrev-commit --decorate --date=relative --pretty=medium %s", branchName)
 }
 
 // GetRemoteURL returns current repo remote url
@@ -591,7 +591,7 @@ func (c *GitCommand) Diff(file *File, plain bool, cached bool) string {
 func (c *GitCommand) DiffCmdStr(file *File, plain bool, cached bool) string {
 	cachedArg := ""
 	trackedArg := "--"
-	colorArg := "--color"
+	colorArg := c.colorArg()
 	split := strings.Split(file.Name, " -> ") // in case of a renamed file we get the new filename
 	fileName := c.OSCommand.Quote(split[len(split)-1])
 	if cached {
@@ -601,10 +601,10 @@ func (c *GitCommand) DiffCmdStr(file *File, plain bool, cached bool) string {
 		trackedArg = "--no-index /dev/null"
 	}
 	if plain {
-		colorArg = ""
+		colorArg = "never"
 	}
 
-	return fmt.Sprintf("git diff --stat -p %s %s %s %s", colorArg, cachedArg, trackedArg, fileName)
+	return fmt.Sprintf("git diff --stat -p --color=%s %s %s %s", colorArg, cachedArg, trackedArg, fileName)
 }
 
 func (c *GitCommand) ApplyPatch(patch string, flags ...string) error {
@@ -896,12 +896,12 @@ func (c *GitCommand) ShowCommitFile(commitSha, fileName string, plain bool) (str
 }
 
 func (c *GitCommand) ShowCommitFileCmdStr(commitSha, fileName string, plain bool) string {
-	colorArg := "--color"
+	colorArg := c.colorArg()
 	if plain {
-		colorArg = ""
+		colorArg = "never"
 	}
 
-	return fmt.Sprintf("git show --no-renames %s %s -- %s", colorArg, commitSha, fileName)
+	return fmt.Sprintf("git show --no-renames --color=%s %s -- %s", colorArg, commitSha, fileName)
 }
 
 // CheckoutFile checks out the file for the given commit
@@ -967,7 +967,7 @@ func (c *GitCommand) ResetSoft(ref string) error {
 
 // DiffCommits show diff between commits
 func (c *GitCommand) DiffCommits(sha1, sha2 string) (string, error) {
-	return c.OSCommand.RunCommandWithOutput("git diff --color --stat -p %s %s", sha1, sha2)
+	return c.OSCommand.RunCommandWithOutput("git diff --color=%s --stat -p %s %s", c.colorArg(), sha1, sha2)
 }
 
 // CreateFixupCommit creates a commit that fixes up a previous commit
@@ -1128,3 +1128,27 @@ func (c *GitCommand) GetReflogCommits() ([]*Commit, error) {
 
 	return commits, nil
 }
+
+func (c *GitCommand) GetPager(width int) (string, error) {
+	pager := c.Config.GetUserConfig().GetString("git.pager")
+	switch pager {
+	case "":
+		return "", nil
+	case "diff-so-fancy":
+		return "diff-so-fancy", nil
+	case "ydiff":
+		return fmt.Sprintf("ydiff -s --wrap --width=%d", width/2-6), nil
+	case "delta":
+		return "delta --dark", nil
+	default:
+		return "", errors.New("pager not supported. Pick one of diff-so-fancy, ydiff, delta, or nothing")
+	}
+}
+
+func (c *GitCommand) colorArg() string {
+	pager := c.Config.GetUserConfig().GetString("git.pager")
+	if pager == "diff-so-fancy" || pager == "" {
+		return "always"
+	}
+	return "never"
+}
diff --git a/pkg/commands/os.go b/pkg/commands/os.go
index e85b3e19c..9cf266f58 100644
--- a/pkg/commands/os.go
+++ b/pkg/commands/os.go
@@ -401,3 +401,11 @@ func (c *OSCommand) PipeCommands(commandStrings ...string) error {
 	}
 	return nil
 }
+
+func Kill(cmd *exec.Cmd) error {
+	if cmd.Process == nil {
+		// somebody got to it before we were able to, poor bastard
+		return nil
+	}
+	return cmd.Process.Kill()
+}
diff --git a/pkg/gui/commit_files_panel.go b/pkg/gui/commit_files_panel.go
index 63458926b..5fa7a4683 100644
--- a/pkg/gui/commit_files_panel.go
+++ b/pkg/gui/commit_files_panel.go
@@ -50,7 +50,7 @@ func (gui *Gui) handleCommitFileSelect(g *gocui.Gui, v *gocui.View) error {
 	cmd := gui.OSCommand.ExecutableFromString(
 		gui.GitCommand.ShowCommitFileCmdStr(commitFile.Sha, commitFile.Name, false),
 	)
-	if err := gui.newCmdTask("main", cmd); err != nil {
+	if err := gui.newPtyTask("main", cmd); err != nil {
 		gui.Log.Error(err)
 	}
 
diff --git a/pkg/gui/commits_panel.go b/pkg/gui/commits_panel.go
index fe6b7acb9..0c901d085 100644
--- a/pkg/gui/commits_panel.go
+++ b/pkg/gui/commits_panel.go
@@ -67,7 +67,7 @@ func (gui *Gui) handleCommitSelect(g *gocui.Gui, v *gocui.View) error {
 	cmd := gui.OSCommand.ExecutableFromString(
 		gui.GitCommand.ShowCmdStr(commit.Sha),
 	)
-	if err := gui.newCmdTask("main", cmd); err != nil {
+	if err := gui.newPtyTask("main", cmd); err != nil {
 		gui.Log.Error(err)
 	}
 
diff --git a/pkg/gui/files_panel.go b/pkg/gui/files_panel.go
index 4e00dc523..6bd2c7076 100644
--- a/pkg/gui/files_panel.go
+++ b/pkg/gui/files_panel.go
@@ -62,7 +62,7 @@ func (gui *Gui) selectFile(alreadySelected bool) error {
 		gui.getSecondaryView().Title = gui.Tr.SLocalize("StagedChanges")
 		cmdStr := gui.GitCommand.DiffCmdStr(file, false, true)
 		cmd := gui.OSCommand.ExecutableFromString(cmdStr)
-		if err := gui.newCmdTask("secondary", cmd); err != nil {
+		if err := gui.newPtyTask("secondary", cmd); err != nil {
 			return err
 		}
 	} else {
@@ -76,7 +76,7 @@ func (gui *Gui) selectFile(alreadySelected bool) error {
 
 	cmdStr := gui.GitCommand.DiffCmdStr(file, false, !file.HasUnstagedChanges && file.HasStagedChanges)
 	cmd := gui.OSCommand.ExecutableFromString(cmdStr)
-	if err := gui.newCmdTask("main", cmd); err != nil {
+	if err := gui.newPtyTask("main", cmd); err != nil {
 		return err
 	}
 
diff --git a/pkg/gui/gui.go b/pkg/gui/gui.go
index 70c3c3f51..9289c4e31 100644
--- a/pkg/gui/gui.go
+++ b/pkg/gui/gui.go
@@ -211,6 +211,9 @@ type guiState struct {
 	Searching            searchingState
 	ScreenMode           int
 	SideView             *gocui.View
+	Ptmx                 *os.File
+	PrevMainWidth        int
+	PrevMainHeight       int
 }
 
 // for now the split view will always be on
@@ -247,6 +250,7 @@ func NewGui(log *logrus.Entry, gitCommand *commands.GitCommand, oSCommand *comma
 		},
 		ScreenMode: SCREEN_NORMAL,
 		SideView:   nil,
+		Ptmx:       nil,
 	}
 
 	gui := &Gui{
@@ -811,6 +815,15 @@ func (gui *Gui) layout(g *gocui.Gui) error {
 		}
 	}
 
+	mainViewWidth, mainViewHeight := gui.getMainView().Size()
+	if mainViewWidth != gui.State.PrevMainWidth || mainViewHeight != gui.State.PrevMainHeight {
+		gui.State.PrevMainWidth = mainViewWidth
+		gui.State.PrevMainHeight = mainViewHeight
+		if err := gui.onResize(); err != nil {
+			return err
+		}
+	}
+
 	// here is a good place log some stuff
 	// if you download humanlog and do tail -f development.log | humanlog
 	// this will let you see these branches as prettified json
@@ -942,7 +955,7 @@ func (gui *Gui) startBackgroundFetch() {
 
 // Run setup the gui with keybindings and start the mainloop
 func (gui *Gui) Run() error {
-	g, err := gocui.NewGui(gocui.OutputNormal, OverlappingEdges)
+	g, err := gocui.NewGui(gocui.Output256, OverlappingEdges)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/gui/pty.go b/pkg/gui/pty.go
new file mode 100644
index 000000000..18fb98fda
--- /dev/null
+++ b/pkg/gui/pty.go
@@ -0,0 +1,21 @@
+package gui
+
+import (
+	"github.com/jesseduffield/pty"
+)
+
+func (gui *Gui) onResize() error {
+	if gui.State.Ptmx == nil {
+		return nil
+	}
+	mainView := gui.getMainView()
+	width, height := mainView.Size()
+
+	if err := pty.Setsize(gui.State.Ptmx, &pty.Winsize{Cols: uint16(width), Rows: uint16(height)}); err != nil {
+		return err
+	}
+
+	// TODO: handle resizing properly
+
+	return nil
+}
diff --git a/pkg/gui/reflog_panel.go b/pkg/gui/reflog_panel.go
index 37144d8c6..1837e2f7d 100644
--- a/pkg/gui/reflog_panel.go
+++ b/pkg/gui/reflog_panel.go
@@ -41,7 +41,7 @@ func (gui *Gui) handleReflogCommitSelect(g *gocui.Gui, v *gocui.View) error {
 	cmd := gui.OSCommand.ExecutableFromString(
 		gui.GitCommand.ShowCmdStr(commit.Sha),
 	)
-	if err := gui.newCmdTask("main", cmd); err != nil {
+	if err := gui.newPtyTask("main", cmd); err != nil {
 		gui.Log.Error(err)
 	}
 
diff --git a/pkg/gui/stash_panel.go b/pkg/gui/stash_panel.go
index db12767e8..92d84df9f 100644
--- a/pkg/gui/stash_panel.go
+++ b/pkg/gui/stash_panel.go
@@ -41,7 +41,7 @@ func (gui *Gui) handleStashEntrySelect(g *gocui.Gui, v *gocui.View) error {
 	cmd := gui.OSCommand.ExecutableFromString(
 		gui.GitCommand.ShowStashEntryCmdStr(stashEntry.Index),
 	)
-	if err := gui.newCmdTask("main", cmd); err != nil {
+	if err := gui.newPtyTask("main", cmd); err != nil {
 		gui.Log.Error(err)
 	}
 
diff --git a/pkg/gui/tasks_adapter.go b/pkg/gui/tasks_adapter.go
index 22ebb9da9..38d7ce36b 100644
--- a/pkg/gui/tasks_adapter.go
+++ b/pkg/gui/tasks_adapter.go
@@ -5,6 +5,7 @@ import (
 
 	"github.com/jesseduffield/gocui"
 	"github.com/jesseduffield/lazygit/pkg/tasks"
+	"github.com/jesseduffield/pty"
 )
 
 func (gui *Gui) newCmdTask(viewName string, cmd *exec.Cmd) error {
@@ -25,6 +26,49 @@ func (gui *Gui) newCmdTask(viewName string, cmd *exec.Cmd) error {
 	return nil
 }
 
+func (gui *Gui) newPtyTask(viewName string, cmd *exec.Cmd) error {
+	width, _ := gui.getMainView().Size()
+	pager, err := gui.GitCommand.GetPager(width)
+	if err != nil {
+		return err
+	}
+
+	if pager == "" {
+		// if we're not using a custom pager we don't need to use a pty
+		return gui.newCmdTask(viewName, cmd)
+	}
+
+	cmd.Env = append(cmd.Env, "GIT_PAGER="+pager)
+
+	view, err := gui.g.View(viewName)
+	if err != nil {
+		return nil // swallowing for now
+	}
+
+	_, height := view.Size()
+	_, oy := view.Origin()
+
+	manager := gui.getManager(view)
+
+	ptmx, err := pty.Start(cmd)
+	if err != nil {
+		return err
+	}
+
+	gui.State.Ptmx = ptmx
+	onClose := func() { gui.State.Ptmx = nil }
+
+	if err := gui.onResize(); err != nil {
+		return err
+	}
+
+	if err := manager.NewTask(manager.NewPtyTask(ptmx, cmd, height+oy+10, onClose)); err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func (gui *Gui) newTask(viewName string, f func(chan struct{}) error) error {
 	view, err := gui.g.View(viewName)
 	if err != nil {
@@ -69,7 +113,10 @@ func (gui *Gui) getManager(view *gocui.View) *tasks.ViewBufferManager {
 				view.Clear()
 			},
 			func() {
-				gui.g.Update(func(*gocui.Gui) error { return nil })
+				gui.g.Update(func(*gocui.Gui) error {
+					gui.Log.Warn("updating view")
+					return nil
+				})
 			})
 		gui.viewBufferManagerMap[view.Name()] = manager
 	}
diff --git a/pkg/tasks/tasks.go b/pkg/tasks/tasks.go
index 26846c439..716de488e 100644
--- a/pkg/tasks/tasks.go
+++ b/pkg/tasks/tasks.go
@@ -4,10 +4,12 @@ import (
 	"bufio"
 	"fmt"
 	"io"
+	"os"
 	"os/exec"
 	"sync"
 	"time"
 
+	"github.com/jesseduffield/lazygit/pkg/commands"
 	"github.com/sirupsen/logrus"
 )
 
@@ -60,7 +62,7 @@ func (m *ViewBufferManager) NewCmdTask(cmd *exec.Cmd, linesToRead int) func(chan
 		go func() {
 			<-stop
 			if cmd.ProcessState == nil {
-				if err := kill(cmd); err != nil {
+				if err := commands.Kill(cmd); err != nil {
 					m.Log.Warn(err)
 				}
 			}
@@ -105,6 +107,95 @@ func (m *ViewBufferManager) NewCmdTask(cmd *exec.Cmd, linesToRead int) func(chan
 
 						select {
 						case <-stop:
+							m.refreshView()
+							break outer
+						default:
+						}
+						if !ok {
+							m.refreshView()
+							break outer
+						}
+						m.writer.Write(append(scanner.Bytes(), []byte("\n")...))
+					}
+					m.refreshView()
+				case <-stop:
+					m.refreshView()
+					break outer
+				}
+			}
+			m.refreshView()
+
+			if err := cmd.Wait(); err != nil {
+				m.Log.Warn(err)
+			}
+
+			close(done)
+		}()
+
+		m.readLines <- linesToRead
+
+		<-done
+
+		return nil
+	}
+}
+
+func (m *ViewBufferManager) NewPtyTask(ptmx *os.File, cmd *exec.Cmd, linesToRead int, onClose func()) func(chan struct{}) error {
+	return func(stop chan struct{}) error {
+		r := ptmx
+
+		defer ptmx.Close()
+
+		done := make(chan struct{})
+		go func() {
+			<-stop
+			commands.Kill(cmd)
+			ptmx.Close()
+		}()
+
+		loadingMutex := sync.Mutex{}
+
+		// not sure if it's the right move to redefine this or not
+		m.readLines = make(chan int, 1024)
+
+		go func() {
+			scanner := bufio.NewScanner(r)
+			scanner.Split(bufio.ScanLines)
+
+			loaded := false
+
+			go func() {
+				ticker := time.NewTicker(time.Millisecond * 100)
+				defer ticker.Stop()
+				select {
+				case <-ticker.C:
+					loadingMutex.Lock()
+					if !loaded {
+						m.beforeStart()
+						m.writer.Write([]byte("loading..."))
+						m.refreshView()
+					}
+					loadingMutex.Unlock()
+				case <-stop:
+					return
+				}
+			}()
+
+		outer:
+			for {
+				select {
+				case linesToRead := <-m.readLines:
+					for i := 0; i < linesToRead; i++ {
+						ok := scanner.Scan()
+						loadingMutex.Lock()
+						if !loaded {
+							m.beforeStart()
+							loaded = true
+						}
+						loadingMutex.Unlock()
+
+						select {
+						case <-stop:
 							break outer
 						default:
 						}
@@ -124,12 +215,18 @@ func (m *ViewBufferManager) NewCmdTask(cmd *exec.Cmd, linesToRead int) func(chan
 				m.Log.Warn(err)
 			}
 
+			m.refreshView()
+
+			onClose()
+
 			close(done)
 		}()
 
 		m.readLines <- linesToRead
 
+		m.Log.Warn("waiting for done channel")
 		<-done
+		m.Log.Warn("done channel returned")
 
 		return nil
 	}
@@ -141,7 +238,7 @@ func (t *ViewBufferManager) Close() {
 		return
 	}
 
-	c := make(chan struct{}, 1)
+	c := make(chan struct{})
 
 	go func() {
 		t.currentTask.Stop()
@@ -170,7 +267,10 @@ func (m *ViewBufferManager) NewTask(f func(stop chan struct{}) error) error {
 
 		m.waitingMutex.Lock()
 		defer m.waitingMutex.Unlock()
+
+		m.Log.Infof("done waiting")
 		if taskID < m.newTaskId {
+			m.Log.Infof("returning cos the task is obsolete")
 			return
 		}
 
@@ -216,13 +316,3 @@ func (t *Task) Stop() {
 	t.stopped = true
 	return
 }
-
-// kill kills a process
-func kill(cmd *exec.Cmd) error {
-	if cmd.Process == nil {
-		// somebody got to it before we were able to, poor bastard
-		return nil
-	}
-
-	return cmd.Process.Kill()
-}