Improve buffer view relocation after jumping to a far-away location

internal/action/actions.go

@@ -879,11 +879,10 @@ func (h *BufPane) Search(str string, useRegex bool, searchDown bool) error {
 		h.Cursor.SetSelectionEnd(match[1])
 		h.Cursor.OrigSelection[0] = h.Cursor.CurSelection[0]
 		h.Cursor.OrigSelection[1] = h.Cursor.CurSelection[1]
-		h.Cursor.GotoLoc(h.Cursor.CurSelection[1])
+		h.GotoLoc(h.Cursor.CurSelection[1])
 		h.Buf.LastSearch = str
 		h.Buf.LastSearchRegex = useRegex
 		h.Buf.HighlightSearch = h.Buf.Settings["hlsearch"].(bool)
-		h.Relocate()
 	} else {
 		h.Cursor.ResetSelection()
 	}
@@ -905,12 +904,11 @@ func (h *BufPane) find(useRegex bool) bool {
 				h.Cursor.SetSelectionEnd(match[1])
 				h.Cursor.OrigSelection[0] = h.Cursor.CurSelection[0]
 				h.Cursor.OrigSelection[1] = h.Cursor.CurSelection[1]
-				h.Cursor.GotoLoc(match[1])
+				h.GotoLoc(match[1])
 			} else {
-				h.Cursor.GotoLoc(h.searchOrig)
+				h.GotoLoc(h.searchOrig)
 				h.Cursor.ResetSelection()
 			}
-			h.Relocate()
 		}
 	}
 	findCallback := func(resp string, canceled bool) {
@@ -925,7 +923,7 @@ func (h *BufPane) find(useRegex bool) bool {
 				h.Cursor.SetSelectionEnd(match[1])
 				h.Cursor.OrigSelection[0] = h.Cursor.CurSelection[0]
 				h.Cursor.OrigSelection[1] = h.Cursor.CurSelection[1]
-				h.Cursor.GotoLoc(h.Cursor.CurSelection[1])
+				h.GotoLoc(h.Cursor.CurSelection[1])
 				h.Buf.LastSearch = resp
 				h.Buf.LastSearchRegex = useRegex
 				h.Buf.HighlightSearch = h.Buf.Settings["hlsearch"].(bool)
@@ -936,7 +934,6 @@ func (h *BufPane) find(useRegex bool) bool {
 		} else {
 			h.Cursor.ResetSelection()
 		}
-		h.Relocate()
 	}
 	pattern := string(h.Cursor.GetSelection())
 	if eventCallback != nil && pattern != "" {
@@ -980,11 +977,10 @@ func (h *BufPane) FindNext() bool {
 		h.Cursor.SetSelectionEnd(match[1])
 		h.Cursor.OrigSelection[0] = h.Cursor.CurSelection[0]
 		h.Cursor.OrigSelection[1] = h.Cursor.CurSelection[1]
-		h.Cursor.Loc = h.Cursor.CurSelection[1]
+		h.GotoLoc(h.Cursor.CurSelection[1])
 	} else {
 		h.Cursor.ResetSelection()
 	}
-	h.Relocate()
 	return true
 }
 
@@ -1007,11 +1003,10 @@ func (h *BufPane) FindPrevious() bool {
 		h.Cursor.SetSelectionEnd(match[1])
 		h.Cursor.OrigSelection[0] = h.Cursor.CurSelection[0]
 		h.Cursor.OrigSelection[1] = h.Cursor.CurSelection[1]
-		h.Cursor.Loc = h.Cursor.CurSelection[1]
+		h.GotoLoc(h.Cursor.CurSelection[1])
 	} else {
 		h.Cursor.ResetSelection()
 	}
-	h.Relocate()
 	return true
 }
 

internal/action/bufpane.go

@@ -13,6 +13,7 @@ import (
 	"github.com/zyedidia/micro/v2/internal/display"
 	ulua "github.com/zyedidia/micro/v2/internal/lua"
 	"github.com/zyedidia/micro/v2/internal/screen"
+	"github.com/zyedidia/micro/v2/internal/util"
 	"github.com/zyedidia/tcell/v2"
 )
 
@@ -235,10 +236,14 @@ type BufPane struct {
 
 	// remember original location of a search in case the search is canceled
 	searchOrig buffer.Loc
+
+	// The pane may not yet be fully initialized after its creation
+	// since we may not know the window geometry yet. In such case we finish
+	// its initialization a bit later, after the initial resize.
+	initialized bool
 }
 
-// NewBufPane creates a new buffer pane with the given window.
-func NewBufPane(buf *buffer.Buffer, win display.BWindow, tab *Tab) *BufPane {
+func newBufPane(buf *buffer.Buffer, win display.BWindow, tab *Tab) *BufPane {
 	h := new(BufPane)
 	h.Buf = buf
 	h.BWindow = win
@@ -247,16 +252,39 @@ func NewBufPane(buf *buffer.Buffer, win display.BWindow, tab *Tab) *BufPane {
 	h.Cursor = h.Buf.GetActiveCursor()
 	h.mouseReleased = true
 
-	config.RunPluginFn("onBufPaneOpen", luar.New(ulua.L, h))
+	return h
+}
 
+// NewBufPane creates a new buffer pane with the given window.
+func NewBufPane(buf *buffer.Buffer, win display.BWindow, tab *Tab) *BufPane {
+	h := newBufPane(buf, win, tab)
+	h.finishInitialize()
 	return h
 }
 
 // NewBufPaneFromBuf constructs a new pane from the given buffer and automatically
 // creates a buf window.
 func NewBufPaneFromBuf(buf *buffer.Buffer, tab *Tab) *BufPane {
 	w := display.NewBufWindow(0, 0, 0, 0, buf)
-	return NewBufPane(buf, w, tab)
+	h := newBufPane(buf, w, tab)
+	// Postpone finishing initializing the pane until we know the actual geometry
+	// of the buf window.
+	return h
+}
+
+// TODO: make sure splitID and tab are set before finishInitialize is called
+func (h *BufPane) finishInitialize() {
+	h.initialRelocate()
+	h.initialized = true
+	config.RunPluginFn("onBufPaneOpen", luar.New(ulua.L, h))
+}
+
+// Resize resizes the pane
+func (h *BufPane) Resize(width, height int) {
+	h.BWindow.Resize(width, height)
+	if !h.initialized {
+		h.finishInitialize()
+	}
 }
 
 // SetTab sets this pane's tab.
@@ -301,7 +329,7 @@ func (h *BufPane) OpenBuffer(b *buffer.Buffer) {
 	h.BWindow.SetBuffer(b)
 	h.Cursor = b.GetActiveCursor()
 	h.Resize(h.GetView().Width, h.GetView().Height)
-	h.Relocate()
+	h.initialRelocate()
 	// Set mouseReleased to true because we assume the mouse is not being
 	// pressed when the editor is opened
 	h.mouseReleased = true
@@ -311,6 +339,43 @@ func (h *BufPane) OpenBuffer(b *buffer.Buffer) {
 	h.lastClickTime = time.Time{}
 }
 
+// GotoLoc moves the cursor to a new location and adjusts the view accordingly.
+// Use GotoLoc when the new location may be far away from the current location.
+func (h *BufPane) GotoLoc(loc buffer.Loc) {
+	sloc := h.SLocFromLoc(loc)
+	d := h.Diff(h.SLocFromLoc(h.Cursor.Loc), sloc)
+
+	h.Cursor.GotoLoc(loc)
+
+	// If the new location is far away from the previous one,
+	// ensure the cursor is at 25% of the window height
+	height := h.BufView().Height
+	if util.Abs(d) >= height {
+		v := h.GetView()
+		v.StartLine = h.Scroll(sloc, -height/4)
+		h.ScrollAdjust()
+		v.StartCol = 0
+	}
+	h.Relocate()
+}
+
+func (h *BufPane) initialRelocate() {
+	sloc := h.SLocFromLoc(h.Cursor.Loc)
+	height := h.BufView().Height
+
+	// If the initial cursor location is far away from the beginning
+	// of the buffer, ensure the cursor is at 25% of the window height
+	v := h.GetView()
+	if h.Diff(display.SLoc{0, 0}, sloc) < height {
+		v.StartLine = display.SLoc{0, 0}
+	} else {
+		v.StartLine = h.Scroll(sloc, -height/4)
+		h.ScrollAdjust()
+	}
+	v.StartCol = 0
+	h.Relocate()
+}
+
 // ID returns this pane's split id.
 func (h *BufPane) ID() uint64 {
 	return h.splitID

internal/action/command.go

@@ -722,7 +722,7 @@ func (h *BufPane) GotoCmd(args []string) {
 			}
 			line = util.Clamp(line-1, 0, h.Buf.LinesNum()-1)
 			col = util.Clamp(col-1, 0, util.CharacterCount(h.Buf.LineBytes(line)))
-			h.Cursor.GotoLoc(buffer.Loc{col, line})
+			h.GotoLoc(buffer.Loc{col, line})
 		} else {
 			line, err := strconv.Atoi(args[0])
 			if err != nil {
@@ -733,9 +733,8 @@ func (h *BufPane) GotoCmd(args []string) {
 				line = h.Buf.LinesNum() + 1 + line
 			}
 			line = util.Clamp(line-1, 0, h.Buf.LinesNum()-1)
-			h.Cursor.GotoLoc(buffer.Loc{0, line})
+			h.GotoLoc(buffer.Loc{0, line})
 		}
-		h.Relocate()
 	}
 }
 
@@ -834,13 +833,11 @@ func (h *BufPane) ReplaceCmd(args []string) {
 
 			h.Cursor.SetSelectionStart(locs[0])
 			h.Cursor.SetSelectionEnd(locs[1])
-			h.Cursor.GotoLoc(locs[0])
+			h.GotoLoc(locs[0])
 			h.Buf.LastSearch = search
 			h.Buf.LastSearchRegex = true
 			h.Buf.HighlightSearch = h.Buf.Settings["hlsearch"].(bool)
 
-			h.Relocate()
-
 			InfoBar.YNPrompt("Perform replacement (y,n,esc)", func(yes, canceled bool) {
 				if !canceled && yes {
 					_, nrunes := h.Buf.ReplaceRegex(locs[0], locs[1], regex, replace)