Avoid redundantly loading previews for search/find (#569)

* Avoid redundantly loading previews for find

* Avoid redundantly loading previews for search

eval.go

@@ -393,31 +393,31 @@ func update(app *app) {
 		app.nav.search = string(app.ui.cmdAccLeft) + string(app.ui.cmdAccRight)
 
 		dir := app.nav.currDir()
+		old := dir.ind
 		dir.ind = app.nav.searchInd
 		dir.pos = app.nav.searchPos
 
-		if err := app.nav.searchNext(); err != nil {
+		if _, err := app.nav.searchNext(); err != nil {
 			app.ui.echoerrf("search: %s: %s", err, app.nav.search)
-			return
+		} else if old != dir.ind {
-		}
-
 			app.ui.loadFile(app.nav, true)
 			app.ui.loadFileInfo(app.nav)
+		}
 	case gOpts.incsearch && app.ui.cmdPrefix == "?":
 		app.nav.search = string(app.ui.cmdAccLeft) + string(app.ui.cmdAccRight)
 
 		dir := app.nav.currDir()
+		old := dir.ind
 		dir.ind = app.nav.searchInd
 		dir.pos = app.nav.searchPos
 
-		if err := app.nav.searchPrev(); err != nil {
+		if _, err := app.nav.searchPrev(); err != nil {
 			app.ui.echoerrf("search: %s: %s", err, app.nav.search)
-			return
+		} else if old != dir.ind {
-		}
-
 			app.ui.loadFile(app.nav, true)
 			app.ui.loadFileInfo(app.nav)
 		}
+	}
 }
 
 func normal(app *app) {
@@ -455,9 +455,9 @@ func insert(app *app, arg string) {
 				return
 			}
 
-			if !app.nav.findNext() {
+			if moved, found := app.nav.findNext(); !found {
 				app.ui.echoerrf("find: pattern not found: %s", app.nav.find)
-			} else {
+			} else if moved {
 				app.ui.loadFile(app.nav, true)
 				app.ui.loadFileInfo(app.nav)
 			}
@@ -484,9 +484,9 @@ func insert(app *app, arg string) {
 				return
 			}
 
-			if !app.nav.findPrev() {
+			if moved, found := app.nav.findPrev(); !found {
 				app.ui.echoerrf("find-back: pattern not found: %s", app.nav.find)
-			} else {
+			} else if moved {
 				app.ui.loadFile(app.nav, true)
 				app.ui.loadFileInfo(app.nav)
 			}
@@ -854,6 +854,8 @@ func (e *callExpr) eval(app *app, args []string) {
 		app.nav.findBack = true
 		app.ui.loadFileInfo(app.nav)
 	case "find-next":
+		dir := app.nav.currDir()
+		old := dir.ind
 		for i := 0; i < e.count; i++ {
 			if app.nav.findBack {
 				app.nav.findPrev()
@@ -861,9 +863,13 @@ func (e *callExpr) eval(app *app, args []string) {
 				app.nav.findNext()
 			}
 		}
+		if old != dir.ind {
 			app.ui.loadFile(app.nav, true)
 			app.ui.loadFileInfo(app.nav)
+		}
 	case "find-prev":
+		dir := app.nav.currDir()
+		old := dir.ind
 		for i := 0; i < e.count; i++ {
 			if app.nav.findBack {
 				app.nav.findNext()
@@ -871,8 +877,10 @@ func (e *callExpr) eval(app *app, args []string) {
 				app.nav.findPrev()
 			}
 		}
+		if old != dir.ind {
 			app.ui.loadFile(app.nav, true)
 			app.ui.loadFileInfo(app.nav)
+		}
 	case "search":
 		app.ui.cmdPrefix = "/"
 		dir := app.nav.currDir()
@@ -890,35 +898,39 @@ func (e *callExpr) eval(app *app, args []string) {
 	case "search-next":
 		for i := 0; i < e.count; i++ {
 			if app.nav.searchBack {
-				if err := app.nav.searchPrev(); err != nil {
+				if moved, err := app.nav.searchPrev(); err != nil {
 					app.ui.echoerrf("search-back: %s: %s", err, app.nav.search)
-					return
+				} else if moved {
-				}
-			} else {
-				if err := app.nav.searchNext(); err != nil {
-					app.ui.echoerrf("search: %s: %s", err, app.nav.search)
-					return
-				}
-			}
-		}
 					app.ui.loadFile(app.nav, true)
 					app.ui.loadFileInfo(app.nav)
+				}
+			} else {
+				if moved, err := app.nav.searchNext(); err != nil {
+					app.ui.echoerrf("search: %s: %s", err, app.nav.search)
+				} else if moved {
+					app.ui.loadFile(app.nav, true)
+					app.ui.loadFileInfo(app.nav)
+				}
+			}
+		}
 	case "search-prev":
 		for i := 0; i < e.count; i++ {
 			if app.nav.searchBack {
-				if err := app.nav.searchNext(); err != nil {
+				if moved, err := app.nav.searchNext(); err != nil {
 					app.ui.echoerrf("search-back: %s: %s", err, app.nav.search)
-					return
+				} else if moved {
-				}
-			} else {
-				if err := app.nav.searchPrev(); err != nil {
-					app.ui.echoerrf("search: %s: %s", err, app.nav.search)
-					return
-				}
-			}
-		}
 					app.ui.loadFile(app.nav, true)
 					app.ui.loadFileInfo(app.nav)
+				}
+			} else {
+				if moved, err := app.nav.searchPrev(); err != nil {
+					app.ui.echoerrf("search: %s: %s", err, app.nav.search)
+				} else if moved {
+					app.ui.loadFile(app.nav, true)
+					app.ui.loadFileInfo(app.nav)
+				}
+			}
+		}
 	case "mark-save":
 		app.ui.cmdPrefix = "mark-save: "
 	case "mark-load":
@@ -1067,12 +1079,13 @@ func (e *callExpr) eval(app *app, args []string) {
 		}
 		if gOpts.incsearch && (app.ui.cmdPrefix == "/" || app.ui.cmdPrefix == "?") {
 			dir := app.nav.currDir()
-			dir.ind = app.nav.searchInd
 			dir.pos = app.nav.searchPos
-
+			if dir.ind != app.nav.searchInd {
+				dir.ind = app.nav.searchInd
 				app.ui.loadFile(app.nav, true)
 				app.ui.loadFileInfo(app.nav)
 			}
+		}
 		normal(app)
 	case "cmd-complete":
 		var matches []string
@@ -1235,32 +1248,34 @@ func (e *callExpr) eval(app *app, args []string) {
 			app.cmdHistory = append(app.cmdHistory, cmdItem{"&", s})
 			app.runShell(s, nil, "&")
 		case "/":
-			if gOpts.incsearch {
 			dir := app.nav.currDir()
+			old := dir.ind
+			if gOpts.incsearch {
 				dir.ind = app.nav.searchInd
 				dir.pos = app.nav.searchPos
 			}
 			log.Printf("search: %s", s)
 			app.ui.cmdPrefix = ""
 			app.nav.search = s
-			if err := app.nav.searchNext(); err != nil {
+			if _, err := app.nav.searchNext(); err != nil {
 				app.ui.echoerrf("search: %s: %s", err, app.nav.search)
-			} else {
+			} else if old != dir.ind {
 				app.ui.loadFile(app.nav, true)
 				app.ui.loadFileInfo(app.nav)
 			}
 		case "?":
-			if gOpts.incsearch {
 			dir := app.nav.currDir()
+			old := dir.ind
+			if gOpts.incsearch {
 				dir.ind = app.nav.searchInd
 				dir.pos = app.nav.searchPos
 			}
 			log.Printf("search-back: %s", s)
 			app.ui.cmdPrefix = ""
 			app.nav.search = s
-			if err := app.nav.searchPrev(); err != nil {
+			if _, err := app.nav.searchPrev(); err != nil {
 				app.ui.echoerrf("search-back: %s: %s", err, app.nav.search)
-			} else {
+			} else if old != dir.ind {
 				app.ui.loadFile(app.nav, true)
 				app.ui.loadFileInfo(app.nav)
 			}

nav.go

@@ -1123,42 +1123,38 @@ func (nav *nav) findSingle() int {
 	return count
 }
 
-func (nav *nav) findNext() bool {
+func (nav *nav) findNext() (bool, bool) {
 	dir := nav.currDir()
 	for i := dir.ind + 1; i < len(dir.files); i++ {
 		if findMatch(dir.files[i].Name(), nav.find) {
-			nav.down(i - dir.ind)
+			return nav.down(i - dir.ind), true
-			return true
 		}
 	}
 	if gOpts.wrapscan {
 		for i := 0; i < dir.ind; i++ {
 			if findMatch(dir.files[i].Name(), nav.find) {
-				nav.up(dir.ind - i)
+				return nav.up(dir.ind - i), true
-				return true
 			}
 		}
 	}
-	return false
+	return false, false
 }
 
-func (nav *nav) findPrev() bool {
+func (nav *nav) findPrev() (bool, bool) {
 	dir := nav.currDir()
 	for i := dir.ind - 1; i >= 0; i-- {
 		if findMatch(dir.files[i].Name(), nav.find) {
-			nav.up(dir.ind - i)
+			return nav.up(dir.ind - i), true
-			return true
 		}
 	}
 	if gOpts.wrapscan {
 		for i := len(dir.files) - 1; i > dir.ind; i-- {
 			if findMatch(dir.files[i].Name(), nav.find) {
-				nav.down(i - dir.ind)
+				return nav.down(i - dir.ind), true
-				return true
 			}
 		}
 	}
-	return false
+	return false, false
 }
 
 func searchMatch(name, pattern string) (matched bool, err error) {
@@ -1182,58 +1178,46 @@ func searchMatch(name, pattern string) (matched bool, err error) {
 	return strings.Contains(name, pattern), nil
 }
 
-func (nav *nav) searchNext() error {
+func (nav *nav) searchNext() (bool, error) {
 	dir := nav.currDir()
 	for i := dir.ind + 1; i < len(dir.files); i++ {
-		matched, err := searchMatch(dir.files[i].Name(), nav.search)
+		if matched, err := searchMatch(dir.files[i].Name(), nav.search); err != nil {
-		if err != nil {
+			return false, err
-			return err
+		} else if matched {
-		}
+			return nav.down(i - dir.ind), nil
-		if matched {
-			nav.down(i - dir.ind)
-			return nil
 		}
 	}
 	if gOpts.wrapscan {
 		for i := 0; i < dir.ind; i++ {
-			matched, err := searchMatch(dir.files[i].Name(), nav.search)
+			if matched, err := searchMatch(dir.files[i].Name(), nav.search); err != nil {
-			if err != nil {
+				return false, err
-				return err
+			} else if matched {
-			}
+				return nav.up(dir.ind - i), nil
-			if matched {
-				nav.up(dir.ind - i)
-				return nil
 			}
 		}
 	}
-	return nil
+	return false, nil
 }
 
-func (nav *nav) searchPrev() error {
+func (nav *nav) searchPrev() (bool, error) {
 	dir := nav.currDir()
 	for i := dir.ind - 1; i >= 0; i-- {
-		matched, err := searchMatch(dir.files[i].Name(), nav.search)
+		if matched, err := searchMatch(dir.files[i].Name(), nav.search); err != nil {
-		if err != nil {
+			return false, err
-			return err
+		} else if matched {
-		}
+			return nav.up(dir.ind - i), nil
-		if matched {
-			nav.up(dir.ind - i)
-			return nil
 		}
 	}
 	if gOpts.wrapscan {
 		for i := len(dir.files) - 1; i > dir.ind; i-- {
-			matched, err := searchMatch(dir.files[i].Name(), nav.search)
+			if matched, err := searchMatch(dir.files[i].Name(), nav.search); err != nil {
-			if err != nil {
+				return false, err
-				return err
+			} else if matched {
-			}
+				return nav.down(i - dir.ind), nil
-			if matched {
-				nav.down(i - dir.ind)
-				return nil
 			}
 		}
 	}
-	return nil
+	return false, nil
 }
 
 func (nav *nav) removeMark(mark string) error {