support line by line additions in staging and patch building contexts

1 files changed, 254 insertions, 0 deletions

diff --git a/pkg/gui/line_by_line_panel.go b/pkg/gui/line_by_line_panel.go
new file mode 100644
index 000000000..f36441823
--- /dev/null
+++ b/pkg/gui/line_by_line_panel.go
@@ -0,0 +1,254 @@
+package gui
+
+import (
+	"github.com/jesseduffield/gocui"
+	"github.com/jesseduffield/lazygit/pkg/commands"
+)
+
+// Currently there are two 'pseudo-panels' that make use of this 'pseudo-panel'.
+// One is the staging panel where we stage files line-by-line, the other is the
+// patch building panel where we add lines of an old commit's file to a patch.
+// This file contains the logic around selecting lines and displaying the diffs
+// staging_panel.go and patch_building_panel.go have functions specific to their
+// use cases
+
+// these represent what select mode we're in
+const (
+	LINE = iota
+	RANGE
+	HUNK
+)
+
+// returns whether the patch is empty so caller can escape if necessary
+// both diffs should be non-coloured because we'll parse them and colour them here
+func (gui *Gui) refreshLineByLinePanel(diff string, secondaryDiff string, secondaryFocused bool) (bool, error) {
+	state := gui.State.Panels.LineByLine
+
+	patchParser, err := commands.NewPatchParser(gui.Log, diff)
+	if err != nil {
+		return false, nil
+	}
+
+	if len(patchParser.StageableLines) == 0 {
+		return true, nil
+	}
+
+	var selectedLineIdx int
+	var firstLineIdx int
+	var lastLineIdx int
+	selectMode := LINE
+	if state != nil {
+		if state.SelectMode == HUNK {
+			// this is tricky: we need to find out which hunk we just staged based on our old `state.PatchParser` (as opposed to the new `patchParser`)
+			// we do this by getting the first line index of the original hunk, then
+			// finding the next stageable line, then getting its containing hunk
+			// in the new diff
+			selectMode = HUNK
+			prevNewHunk := state.PatchParser.GetHunkContainingLine(state.SelectedLineIdx, 0)
+			selectedLineIdx = patchParser.GetNextStageableLineIndex(prevNewHunk.FirstLineIdx)
+			newHunk := patchParser.GetHunkContainingLine(selectedLineIdx, 0)
+			firstLineIdx, lastLineIdx = newHunk.FirstLineIdx, newHunk.LastLineIdx
+		} else {
+			selectedLineIdx = patchParser.GetNextStageableLineIndex(state.SelectedLineIdx)
+			firstLineIdx, lastLineIdx = selectedLineIdx, selectedLineIdx
+		}
+	} else {
+		selectedLineIdx = patchParser.StageableLines[0]
+		firstLineIdx, lastLineIdx = selectedLineIdx, selectedLineIdx
+	}
+
+	gui.State.Panels.LineByLine = &lineByLinePanelState{
+		PatchParser:      patchParser,
+		SelectedLineIdx:  selectedLineIdx,
+		SelectMode:       selectMode,
+		FirstLineIdx:     firstLineIdx,
+		LastLineIdx:      lastLineIdx,
+		Diff:             diff,
+		SecondaryFocused: secondaryFocused,
+	}
+
+	if err := gui.refreshMainView(); err != nil {
+		return false, err
+	}
+
+	if err := gui.focusSelection(selectMode == HUNK); err != nil {
+		return false, err
+	}
+
+	secondaryView := gui.getSecondaryView()
+	secondaryView.Highlight = true
+	secondaryView.Wrap = false
+
+	secondaryPatchParser, err := commands.NewPatchParser(gui.Log, secondaryDiff)
+	if err != nil {
+		return false, nil
+	}
+
+	gui.g.Update(func(*gocui.Gui) error {
+		return gui.setViewContent(gui.g, gui.getSecondaryView(), secondaryPatchParser.Render(-1, -1, nil))
+	})
+
+	return false, nil
+}
+
+func (gui *Gui) handleSelectPrevLine(g *gocui.Gui, v *gocui.View) error {
+	return gui.handleCycleLine(-1)
+}
+
+func (gui *Gui) handleSelectNextLine(g *gocui.Gui, v *gocui.View) error {
+	return gui.handleCycleLine(1)
+}
+
+func (gui *Gui) handleSelectPrevHunk(g *gocui.Gui, v *gocui.View) error {
+	return gui.handleCycleHunk(-1)
+}
+
+func (gui *Gui) handleSelectNextHunk(g *gocui.Gui, v *gocui.View) error {
+	return gui.handleCycleHunk(1)
+}
+
+func (gui *Gui) handleCycleHunk(change int) error {
+	state := gui.State.Panels.LineByLine
+	newHunk := state.PatchParser.GetHunkContainingLine(state.SelectedLineIdx, change)
+	state.SelectedLineIdx = state.PatchParser.GetNextStageableLineIndex(newHunk.FirstLineIdx)
+	if state.SelectMode == HUNK {
+		state.FirstLineIdx, state.LastLineIdx = newHunk.FirstLineIdx, newHunk.LastLineIdx
+	} else {
+		state.FirstLineIdx, state.LastLineIdx = state.SelectedLineIdx, state.SelectedLineIdx
+	}
+
+	if err := gui.refreshMainView(); err != nil {
+		return err
+	}
+
+	return gui.focusSelection(true)
+}
+
+func (gui *Gui) handleCycleLine(change int) error {
+	state := gui.State.Panels.LineByLine
+
+	if state.SelectMode == HUNK {
+		return gui.handleCycleHunk(change)
+	}
+
+	newSelectedLineIdx := state.SelectedLineIdx + change
+	if newSelectedLineIdx < 0 {
+		newSelectedLineIdx = 0
+	} else if newSelectedLineIdx > len(state.PatchParser.PatchLines)-1 {
+		newSelectedLineIdx = len(state.PatchParser.PatchLines) - 1
+	}
+
+	state.SelectedLineIdx = newSelectedLineIdx
+
+	if state.SelectMode == RANGE {
+		if state.SelectedLineIdx < state.FirstLineIdx {
+			state.FirstLineIdx = state.SelectedLineIdx
+		} else {
+			state.LastLineIdx = state.SelectedLineIdx
+		}
+	} else {
+		state.LastLineIdx = state.SelectedLineIdx
+		state.FirstLineIdx = state.SelectedLineIdx
+	}
+
+	if err := gui.refreshMainView(); err != nil {
+		return err
+	}
+
+	return gui.focusSelection(false)
+}
+
+func (gui *Gui) refreshMainView() error {
+	state := gui.State.Panels.LineByLine
+
+	var includedLineIndices []int
+	// I'd prefer not to have knowledge of contexts using this file but I'm not sure
+	// how to get around this
+	if gui.State.Contexts["main"] == "patch-building" {
+		filename := gui.State.CommitFiles[gui.State.Panels.CommitFiles.SelectedLine].Name
+		includedLineIndices = gui.GitCommand.PatchManager.GetFileIncLineIndices(filename)
+	}
+	colorDiff := state.PatchParser.Render(state.FirstLineIdx, state.LastLineIdx, includedLineIndices)
+
+	mainView := gui.getMainView()
+	mainView.Highlight = true
+	mainView.Wrap = false
+
+	gui.g.Update(func(*gocui.Gui) error {
+		return gui.setViewContent(gui.g, gui.getMainView(), colorDiff)
+	})
+
+	return nil
+}
+
+// focusSelection works out the best focus for the staging panel given the
+// selected line and size of the hunk
+func (gui *Gui) focusSelection(includeCurrentHunk bool) error {
+	stagingView := gui.getMainView()
+	state := gui.State.Panels.LineByLine
+
+	_, viewHeight := stagingView.Size()
+	bufferHeight := viewHeight - 1
+	_, origin := stagingView.Origin()
+
+	firstLineIdx := state.SelectedLineIdx
+	lastLineIdx := state.SelectedLineIdx
+
+	if includeCurrentHunk {
+		hunk := state.PatchParser.GetHunkContainingLine(state.SelectedLineIdx, 0)
+		firstLineIdx = hunk.FirstLineIdx
+		lastLineIdx = hunk.LastLineIdx
+	}
+
+	margin := 0 // we may want to have a margin in place to show context  but right now I'm thinking we keep this at zero
+
+	var newOrigin int
+	if firstLineIdx-origin < margin {
+		newOrigin = firstLineIdx - margin
+	} else if lastLineIdx-origin > bufferHeight-margin {
+		newOrigin = lastLineIdx - bufferHeight + margin
+	} else {
+		newOrigin = origin
+	}
+
+	gui.g.Update(func(*gocui.Gui) error {
+		if err := stagingView.SetOrigin(0, newOrigin); err != nil {
+			return err
+		}
+
+		return stagingView.SetCursor(0, state.SelectedLineIdx-newOrigin)
+	})
+
+	return nil
+}
+
+func (gui *Gui) handleToggleSelectRange(g *gocui.Gui, v *gocui.View) error {
+	state := gui.State.Panels.LineByLine
+	if state.SelectMode == RANGE {
+		state.SelectMode = LINE
+	} else {
+		state.SelectMode = RANGE
+	}
+	state.FirstLineIdx, state.LastLineIdx = state.SelectedLineIdx, state.SelectedLineIdx
+
+	return gui.refreshMainView()
+}
+
+func (gui *Gui) handleToggleSelectHunk(g *gocui.Gui, v *gocui.View) error {
+	state := gui.State.Panels.LineByLine
+
+	if state.SelectMode == HUNK {
+		state.SelectMode = LINE
+		state.FirstLineIdx, state.LastLineIdx = state.SelectedLineIdx, state.SelectedLineIdx
+	} else {
+		state.SelectMode = HUNK
+		selectedHunk := state.PatchParser.GetHunkContainingLine(state.SelectedLineIdx, 0)
+		state.FirstLineIdx, state.LastLineIdx = selectedHunk.FirstLineIdx, selectedHunk.LastLineIdx
+	}
+
+	if err := gui.refreshMainView(); err != nil {
+		return err
+	}
+
+	return gui.focusSelection(state.SelectMode == HUNK)
+}