reworking react

Author: grantnelson-wf

playground/internal/common/codeBoxWrapper.go

@@ -0,0 +1,22 @@
+package common
+
+// CodeBoxWrapper represents a code box that allows getting and setting
+// the code and selection, as well as emitting events.
+//
+// This interface allows the code box implementation to be replaced
+// with a mock implementation for testing.
+type CodeBoxWrapper interface {
+	Code() string
+	GetSelection() Selection
+	SetCode(sel Selection, code string)
+	EmitEvent(event Event)
+}
+
+type Event string
+
+const (
+	EscapeEvent Event = `escape`
+	SaveEvent   Event = `save`
+	UndoEvent   Event = `undo`
+	RedoEvent   Event = `redo`
+)

playground/internal/common/selection.go

@@ -0,0 +1,21 @@
+package common
+
+// Selection represents a text selection in the code editor.
+//
+// The selection is defined by the start and end byte offsets in the code string.
+// The start and end offsets are inclusive of the start and exclusive of the end.
+//
+// Typically the start is less than or equal to the end even with a reverse selection,
+// since the CodeBoxWrapper should normalize the selection before returning it and
+// should keep the same selection direction when setting a new selection.
+type Selection struct {
+	Start int
+	End   int
+}
+
+// IsCaret returns true if the selection represents a caret position
+// (i.e. start and end are the same).
+// See https://en.wikipedia.org/wiki/Caret_navigation
+func (sel Selection) IsCaret() bool {
+	return sel.Start == sel.End
+}

playground/internal/common/undoRedo.go

@@ -0,0 +1,23 @@
+package common
+
+type UndoRedoStack interface {
+	PerformUndo(cb CodeBoxWrapper)
+
+	PerformRedo(cb CodeBoxWrapper)
+
+	// AddBreak makes any prior changes not joined into any future changes.
+	//
+	// This should be called when the user makes a change and there is an
+	// automatic code modification such as auto-formatting or auto-completion.
+	// This allows the user to unto the autmatic change separately from their
+	// own change.
+	//
+	// TODO(grantnelson-wf): Insert AddBreak into editor where appropriate.
+	AddBreak()
+
+	// RecordSelectionChange records a selection change without a code change
+	// and adds a break to prevent joining with prior changes.
+	RecordSelectionChange(cb CodeBoxWrapper)
+
+	RecordCodeChange(cb CodeBoxWrapper, priorCode string)
+}

playground/internal/editor/editor.go

@@ -6,40 +6,18 @@ package editor
 import (
 	"strings"
 	"unicode"
+
+	"github.com/gopherjs/gopherjs.github.io/playground/internal/common"
 )
 
 const (
 	// TabWidth is the number of spaces per tab.
 	TabWidth = 4
 
-	EscapeEvent = `escape`
-	SaveEvent   = `save`
-	UndoEvent   = `undo`
-	RedoEvent   = `redo`
-
 	commentPrefix    = `// `
 	commentPrefixLen = len(commentPrefix)
 )
 
-type CodeBoxWrapper interface {
-	Code() string
-	GetSelection() Selection
-	SetCode(sel Selection, code string)
-	EmitEvent(event string)
-}
-
-type Selection struct {
-	Start int
-	End   int
-}
-
-// IsCaret returns true if the selection represents a caret position
-// (i.e. start and end are the same).
-// See https://en.wikipedia.org/wiki/Caret_navigation
-func (sel Selection) IsCaret() bool {
-	return sel.Start == sel.End
-}
-
 // MeasureLineLength returns the length of the line.
 // This counts tabs as multiple spaces so that the visual horizontal offset
 // is correct, assuming a monospace font.
@@ -84,12 +62,12 @@ func LongestMeasuredLineLength(code string) int {
 	return longest
 }
 
-func ProcessKeyDown(wrapper CodeBoxWrapper, key string, shift, ctrl bool) bool {
+func ProcessKeyDown(wrapper common.CodeBoxWrapper, key string, shift, ctrl bool) bool {
 	ce := &codeEditor{CodeBoxWrapper: wrapper}
 	return ce.handleKeyDown(key, shift, ctrl)
 }
 
-type codeEditor struct{ CodeBoxWrapper }
+type codeEditor struct{ common.CodeBoxWrapper }
 
 func (ce *codeEditor) handleKeyDown(key string, shift, ctrl bool) bool {
 	switch key {
@@ -184,7 +162,7 @@ func (ce *codeEditor) handleSpace(shift, ctrl bool) bool {
 	write(newCode, code[caret:])
 
 	caret = lineStart + tabs + spaces
-	newSel := Selection{Start: caret, End: caret}
+	newSel := common.Selection{Start: caret, End: caret}
 	ce.SetCode(newSel, newCode.String())
 	return true
 }
@@ -215,7 +193,7 @@ func (ce *codeEditor) handleTab(shift, ctrl bool) bool {
 func (ce *codeEditor) addIndents() bool {
 	lineSel := ce.getSelectedLines()
 	nonBlankLines := 0
-	ce.foreachLine(lineSel, func(line string, _ Selection) bool {
+	ce.foreachLine(lineSel, func(line string, _ common.Selection) bool {
 		if !isBlankLine(line) {
 			nonBlankLines++
 		}
@@ -233,7 +211,7 @@ func (ce *codeEditor) addIndents() bool {
 	newCode.Grow(len(code) + nonBlankLines)
 
 	write(newCode, code[:lineSel.Start])
-	ce.foreachLine(lineSel, func(line string, curLineSel Selection) bool {
+	ce.foreachLine(lineSel, func(line string, curLineSel common.Selection) bool {
 		if isBlankLine(line) {
 			write(newCode, line) // Empty line, just add as-is.
 			return true
@@ -253,7 +231,7 @@ func (ce *codeEditor) addIndents() bool {
 func (ce *codeEditor) removeIndents() bool {
 	lineSel := ce.getSelectedLines()
 	indentedLines := 0
-	ce.foreachLine(lineSel, func(line string, _ Selection) bool {
+	ce.foreachLine(lineSel, func(line string, _ common.Selection) bool {
 		if line[0] == '\t' || line[0] == ' ' {
 			indentedLines++
 		}
@@ -271,7 +249,7 @@ func (ce *codeEditor) removeIndents() bool {
 	newCode.Grow(len(code) - indentedLines) // assumes tabs are being removed
 
 	write(newCode, code[:lineSel.Start])
-	ce.foreachLine(lineSel, func(line string, curLineSel Selection) bool {
+	ce.foreachLine(lineSel, func(line string, curLineSel common.Selection) bool {
 		// Trim up to one tab or equivalent spaces.
 		removeChars := 0
 		for i := 0; i < len(line); i++ {
@@ -367,12 +345,12 @@ func (ce *codeEditor) handleSave(shift, ctrl bool) bool {
 		return false
 	}
 
-	ce.EmitEvent(SaveEvent)
+	ce.EmitEvent(common.SaveEvent)
 	return true
 }
 
 func (ce *codeEditor) handleEscape() bool {
-	ce.EmitEvent(EscapeEvent)
+	ce.EmitEvent(common.EscapeEvent)
 	return true
 }
 
@@ -383,11 +361,11 @@ func (ce *codeEditor) handleUndo(shift, ctrl bool) bool {
 	}
 
 	if shift {
-		ce.EmitEvent(RedoEvent)
+		ce.EmitEvent(common.RedoEvent)
 		return true
 	}
 
-	ce.EmitEvent(UndoEvent)
+	ce.EmitEvent(common.UndoEvent)
 	return true
 }
 
@@ -397,7 +375,7 @@ func (ce *codeEditor) handleRedo(shift, ctrl bool) bool {
 		return false
 	}
 
-	ce.EmitEvent(RedoEvent)
+	ce.EmitEvent(common.RedoEvent)
 	return true
 }
 
@@ -411,7 +389,7 @@ func (ce *codeEditor) handleCommentToggle(shift, ctrl bool) bool {
 	lineSel := ce.getSelectedLines()
 	containsOnlyBlankLines := true
 	containsUncommentedLine := false
-	ce.foreachLine(lineSel, func(line string, _ Selection) bool {
+	ce.foreachLine(lineSel, func(line string, _ common.Selection) bool {
 		if trimmed := trimLeftSpace(line); trimmed != `` {
 			containsOnlyBlankLines = false
 			if !strings.HasPrefix(trimmed, commentPrefix) {
@@ -438,10 +416,10 @@ func (ce *codeEditor) handleCommentToggle(shift, ctrl bool) bool {
 
 // addCommenting will add the comment prefix to each non-blank line in
 // the given range including any lines that already are commented.
-func (ce *codeEditor) addCommenting(lineSel Selection) {
+func (ce *codeEditor) addCommenting(lineSel common.Selection) {
 	leastIndent := -1
 	nonBlankLines := 0
-	ce.foreachLine(lineSel, func(line string, _ Selection) bool {
+	ce.foreachLine(lineSel, func(line string, _ common.Selection) bool {
 		if trimmed := trimLeftSpace(line); trimmed != `` {
 			if indent := len(line) - len(trimmed); leastIndent < 0 || indent < leastIndent {
 				leastIndent = indent
@@ -465,7 +443,7 @@ func (ce *codeEditor) addCommenting(lineSel Selection) {
 	newCode.Grow(len(code) + nonBlankLines*commentPrefixLen)
 
 	write(newCode, code[:lineSel.Start])
-	ce.foreachLine(lineSel, func(line string, curLineSel Selection) bool {
+	ce.foreachLine(lineSel, func(line string, curLineSel common.Selection) bool {
 		if isBlankLine(line) {
 			write(newCode, line) // Empty line, just add as-is.
 			return true
@@ -483,15 +461,15 @@ func (ce *codeEditor) addCommenting(lineSel Selection) {
 
 // removeCommenting will uncomment any line that starts with the comment prefix
 // (and preceding whitespace).
-func (ce *codeEditor) removeCommenting(lineSel Selection) {
+func (ce *codeEditor) removeCommenting(lineSel common.Selection) {
 	code := ce.Code()
 	sel := ce.GetSelection()
 	newSel := sel
 	newCode := &strings.Builder{}
 	newCode.Grow(len(code))
 
 	write(newCode, code[:lineSel.Start])
-	ce.foreachLine(lineSel, func(line string, curLineSel Selection) bool {
+	ce.foreachLine(lineSel, func(line string, curLineSel common.Selection) bool {
 		if trimmed := trimLeftSpace(line); trimmed != `` {
 			if index := strings.Index(line, commentPrefix); index >= 0 {
 				write(newCode, line[:index])
@@ -514,11 +492,11 @@ func (ce *codeEditor) removeCommenting(lineSel Selection) {
 // or at the front of all the code.
 // The returned end should be after the "\n" after the selection
 // or at the end of all the code.
-func (ce *codeEditor) getSelectedLines() Selection {
+func (ce *codeEditor) getSelectedLines() common.Selection {
 	code := ce.Code()
 	codeLen := len(code)
 	sel := ce.GetSelection()
-	lineSel := Selection{Start: 0, End: codeLen}
+	lineSel := common.Selection{Start: 0, End: codeLen}
 	if inRange(sel.Start, 0, codeLen) {
 		lineSel.Start = findStartOfLastLine(code[:sel.Start])
 	}
@@ -542,12 +520,12 @@ func (ce *codeEditor) getSelectedLines() Selection {
 //
 // If the yield function returns false, iteration stops and
 // foreachLine returns false. Otherwise, it returns true.
-func (ce *codeEditor) foreachLine(sel Selection, yield func(line string, curLineSel Selection) bool) bool {
+func (ce *codeEditor) foreachLine(sel common.Selection, yield func(line string, curLineSel common.Selection) bool) bool {
 	code := ce.Code()
 	for i := sel.Start; i < sel.End; {
 		lineEnd := findEndOfLineAfter(i, code[:sel.End])
 		line := code[i:lineEnd]
-		if !yield(line, Selection{i, lineEnd}) {
+		if !yield(line, common.Selection{Start: i, End: lineEnd}) {
 			return false
 		}
 		i = lineEnd
@@ -568,7 +546,7 @@ func (ce *codeEditor) insertPair(ctrl bool, before, after string) bool {
 func (ce *codeEditor) insertAtSelection(before, after string, keepSelection bool) {
 	code := ce.Code()
 	sel := ce.GetSelection()
-	newSel := Selection{Start: sel.Start, End: sel.Start} // set both to start initially
+	newSel := common.Selection{Start: sel.Start, End: sel.Start} // set both to start initially
 
 	beforeLen := len(before)
 	afterLen := len(after)
@@ -670,7 +648,7 @@ func inRange(value, start, end int) bool {
 // if the current selection is after the given limit.
 // This moves the selection based on where new text is being inserted at or
 // removed from the limit position.
-func adjustSel(newSel *Selection, curSel Selection, limit, adjustment int) {
+func adjustSel(newSel *common.Selection, curSel common.Selection, limit, adjustment int) {
 	if curSel.Start > limit {
 		newSel.Start += adjustment
 	}