adding tabModeSearch to search in page (#240)

* adding tabModeSearch to search in page

* skipping tag regions in text search

* formatted and fixed linter errors

* fixed non-exhaustive switch case

* adding keybindings to default-config.toml and help.go

* change search keybindings to vim/less defaults

* updated tag regex and compiled it once globally

* use existing bottomBar for search

* adding resetSearch helper function

* remove redundant bool

* go fmt

---------

Co-authored-by: Robin Schubert <robin.schubert@ghi-muenster.de>
Co-authored-by: makeworld <makeworld@protonmail.com>

config/config.go

@@ -254,6 +254,9 @@ func Init() error {
 	viper.SetDefault("keybindings.bind_copy_target_url", "c")
 	viper.SetDefault("keybindings.bind_beginning", []string{"Home", "g"})
 	viper.SetDefault("keybindings.bind_end", []string{"End", "G"})
+	viper.SetDefault("keybindings.bind_search", "/")
+	viper.SetDefault("keybindings.bind_next_match", "n")
+	viper.SetDefault("keybindings.bind_prev_match", "N")
 	viper.SetDefault("keybindings.shift_numbers", "")
 	viper.SetDefault("keybindings.bind_url_handler_open", "Ctrl-U")
 	viper.SetDefault("url-handlers.other", "default")

config/default.go

@@ -190,6 +190,11 @@ underline = true
 # bind_end: same but the for the end (bottom left)
 # bind_url_handler_open: Open highlighted URL with URL handler (#143)
 
+# Search
+# bind_search = "/"
+# bind_next_match = "n"
+# bind_prev_match = "N"
+
 [url-handlers]
 # Allows setting the commands to run for various URL schemes.
 # E.g. to open FTP URLs with FileZilla set the following key:

config/keybindings.go

@@ -62,6 +62,9 @@ const (
 	CmdBeginning
 	CmdEnd
 	CmdURLHandlerOpen // See #143
+	CmdSearch
+	CmdNextMatch
+	CmdPrevMatch
 )
 
 type keyBinding struct {
@@ -200,6 +203,9 @@ func KeyInit() {
 		CmdBeginning:      "keybindings.bind_beginning",
 		CmdEnd:            "keybindings.bind_end",
 		CmdURLHandlerOpen: "keybindings.bind_url_handler_open",
+		CmdSearch:		     "keybindings.bind_search",
+		CmdNextMatch:	     "keybindings.bind_next_match",
+		CmdPrevMatch:	     "keybindings.bind_prev_match",
 	}
 	// This is split off to allow shift_numbers to override bind_tab[1-90]
 	// (This is needed for older configs so that the default bind_tab values

default-config.toml

@@ -187,6 +187,11 @@ underline = true
 # bind_end: same but the for the end (bottom left)
 # bind_url_handler_open: Open highlighted URL with URL handler (#143)
 
+# Search
+# bind_search = "/"
+# bind_next_match = "n"
+# bind_prev_match = "N"
+
 [url-handlers]
 # Allows setting the commands to run for various URL schemes.
 # E.g. to open FTP URLs with FileZilla set the following key:

display/display.go

@@ -29,6 +29,14 @@ var termH int
 // The user input and URL display bar at the bottom
 var bottomBar = cview.NewInputField()
 
+var originalText []byte
+var tagsRegex = regexp.MustCompile(`\[[a-zA-Z0-9_,;: \-\."#]+[^\[]*\]`)
+var searchMode = false
+var searchString = ""
+var bottomBarText = ""
+var matches = 0
+var curMatch = 0
+
 // When the bottom bar string has a space, this regex decides whether it's
 // a non-encoded URL or a search string.
 // See this comment for details:
@@ -139,6 +147,9 @@ func Init(version, commit, builtBy string) {
 		// Reset func to set the bottomBar back to what it was before
 		// Use for errors.
 		reset := func() {
+			if searchMode {
+				resetSearch()
+			}
 			bottomBar.SetLabel("")
 			tabs[tab].applyAll()
 			App.SetFocus(tabs[tab].view)
@@ -147,6 +158,63 @@ func Init(version, commit, builtBy string) {
 		//nolint:exhaustive
 		switch key {
 		case tcell.KeyEnter:
+
+			if searchMode {
+				// Escape the search string to not find regexp symbols
+				searchString = regexp.QuoteMeta(bottomBar.GetText())
+
+				if strings.TrimSpace(searchString) == "" {
+					// Ignore
+					reset()
+					return
+				}
+
+				if tabs[tab].mode != tabModeSearch {
+					originalText = tabs[curTab].view.GetBytes(false)
+				}
+				tabs[tab].mode = tabModeSearch
+
+				// find all positions of the search string
+				searchRegex := regexp.MustCompile(searchString)
+				searchIdx := searchRegex.FindAllIndex(originalText, -1)
+
+				// find all positions of tags
+				tagsIdx := tagsRegex.FindAllIndex(originalText, -1)
+
+				text := make([]byte, 0)
+				matches = 0
+				lastMatch := 0
+
+				// loops through all occurrences and check if they
+				// discard if they lie within tags.
+				// []byte text is build from the original text buffer
+				// with the actual search strings replaced by tagged regions
+				// to highlight.
+				for i, match := range searchIdx {
+					for _, tag := range tagsIdx {
+						if match[0] >= tag[0] && match[1] <= tag[1] {
+							break
+						}
+					}
+
+					matches++
+					text = append(text, originalText[lastMatch:match[0]]...)
+					replacement := []byte(fmt.Sprint(`["search-`, i, `"]`, searchString, `[""]`))
+					text = append(text, replacement...)
+					lastMatch = match[0] + len(searchString)
+				}
+				text = append(text, originalText[lastMatch:]...)
+
+				tabs[curTab].view.SetBytes(text)
+
+				curMatch = 0
+				tabs[curTab].view.Highlight(fmt.Sprint("search-", "0"))
+				tabs[curTab].view.ScrollToHighlight()
+				App.SetFocus(tabs[tab].view)
+
+				return
+			}
+
 			// Figure out whether it's a URL, link number, or search
 			// And send out a request
 
@@ -305,6 +373,31 @@ func Init(version, commit, builtBy string) {
 		// keybinding in config/config.go and update the help panel in display/help.go
 
 		cmd := config.TranslateKeyEvent(event)
+		if tabs[curTab].mode == tabModeSearch {
+			switch cmd {
+			case config.CmdNextMatch:
+				if curMatch < (matches - 1) {
+					curMatch++
+					tabs[curTab].view.Highlight(fmt.Sprint("search-", curMatch))
+				}
+				tabs[curTab].view.ScrollToHighlight()
+				return nil
+			case config.CmdPrevMatch:
+				if curMatch > 0 {
+					curMatch--
+					tabs[curTab].view.Highlight(fmt.Sprint("search-", curMatch))
+				}
+				tabs[curTab].view.ScrollToHighlight()
+				return nil
+			case config.CmdInvalid:
+				if event.Key() == tcell.KeyEsc {
+					resetSearch()
+					return nil
+				}
+			}
+			return event
+		}
+
 		if tabs[curTab].mode == tabModeDone {
 			// All the keys and operations that can only work while NOT loading
 			//nolint:exhaustive
@@ -322,6 +415,13 @@ func Init(version, commit, builtBy string) {
 				// Don't save bottom bar, so that whenever you switch tabs, it's not in that mode
 				App.SetFocus(bottomBar)
 				return nil
+			case config.CmdSearch:
+				bottomBar.SetLabel("[::b]Search: [::-]")
+				bottomBarText = bottomBar.GetText()
+				bottomBar.SetText("")
+				searchMode = true
+				App.SetFocus(bottomBar)
+				return nil
 			case config.CmdEdit:
 				// Letter e allows to edit current URL
 				bottomBar.SetLabel("[::b]Edit URL: [::-]")
@@ -578,3 +678,11 @@ func renderPageFromString(str string) *structs.Page {
 func NumTabs() int {
 	return len(tabs)
 }
+
+func resetSearch() {
+	tabs[curTab].view.SetBytes(originalText)
+	tabs[curTab].mode = tabModeDone
+	searchMode = false
+	bottomBar.SetLabel("")
+	bottomBar.SetText(bottomBarText)
+}

display/help.go

@@ -49,6 +49,9 @@ var helpCells = strings.TrimSpace(
 		"%s\tSave the current page to your downloads.\n" +
 		"%s\tView subscriptions\n" +
 		"%s\tAdd or update a subscription\n" +
+		"%s\tSearch the page content for a string\n" +
+		"%s\tFind next search match\n" +
+		"%s\tFind previous search match\n" +
 		"%s\tQuit\n")
 
 var helpTable = cview.NewTextView()
@@ -110,6 +113,9 @@ func helpInit() {
 		config.GetKeyBinding(config.CmdSave),
 		config.GetKeyBinding(config.CmdSub),
 		config.GetKeyBinding(config.CmdAddSub),
+		config.GetKeyBinding(config.CmdSearch),
+		config.GetKeyBinding(config.CmdNextMatch),
+		config.GetKeyBinding(config.CmdPrevMatch),
 		config.GetKeyBinding(config.CmdQuit),
 	)
 

display/tab.go

@@ -19,6 +19,7 @@ type tabMode int
 const (
 	tabModeDone tabMode = iota
 	tabModeLoading
+	tabModeSearch
 )
 
 // tabHistoryPageCache is fields from the Page struct, cached here to solve #122

display/thanks.go

@@ -1,4 +1,4 @@
-//nolint
+// nolint
 package display
 
 //go:generate ./thanks.sh