Add a TestField widget that supports a cursor.

firmware/application/ui/ui_alphanum.cpp

@@ -30,10 +30,6 @@
 
 namespace ui {
 
-void AlphanumView::paint(Painter&) {
-	draw_cursor();
-}
-
 AlphanumView::AlphanumView(
 	NavigationView& nav,
 	std::string& str,
@@ -77,16 +73,7 @@ AlphanumView::AlphanumView(
 	field_raw.set_value('0');
 	field_raw.on_select = [this](NumberField&) {
 		char_add(field_raw.value());
-		update_text();
 	};
-
-	button_ok.on_select = [this, &nav](Button&) {
-		if (on_changed)
-			on_changed(_str);
-		nav.pop();
-	};
-
-	update_text();
 }
 
 void AlphanumView::set_mode(const uint32_t new_mode) {
@@ -120,8 +107,6 @@ void AlphanumView::on_button(Button& button) {
 		char_delete();
 	else
 		char_add(c);
-	
-	update_text();
 }
 
 bool AlphanumView::on_encoder(const EncoderEvent delta) {

firmware/application/ui/ui_alphanum.hpp

@@ -40,7 +40,6 @@ public:
 	AlphanumView& operator=(const AlphanumView&) = delete;
 	AlphanumView& operator=(AlphanumView&&) = delete;
 
-	void paint(Painter& painter) override;
 	bool on_encoder(const EncoderEvent delta) override;
 
 private:

firmware/application/ui/ui_textentry.cpp

@@ -45,76 +45,191 @@ void text_prompt(NavigationView& nav, std::string& str, const size_t max_length,
 	}*/
 }
 
-void TextEntryView::update_text() {
-	if (cursor_pos < 30)
-		text_input.set(_str + std::string(_max_length - _str.length(), ' '));
-	else
-		text_input.set('<' + _str.substr(cursor_pos - 29, 29));
+/* TextField ***********************************************************/
 
-	draw_cursor();
+TextField::TextField(
+	std::string& str,
+	size_t max_length,
+	Point position,
+	uint32_t length
+) : Widget{ { position, { 8 * static_cast<int>(length), 16 } } },
+	text_{ str },
+	max_length_{ std::max<size_t>(max_length, 1) },
+	char_count_{ std::max<uint32_t>(length, 1) },
+	cursor_pos_{ text_.length() },
+	insert_mode_{ true }
+{
+	set_focusable(true);
 }
 
-void TextEntryView::char_delete() {
-	if (!cursor_pos) return;
+const std::string& TextField::value() const {
+	return text_;
+}
 
-	cursor_pos--;
-	_str.resize(cursor_pos);
+void TextField::set(const std::string& str) {
+	// Assume that setting the string implies we want the whole thing.
+	max_length_ = std::max(max_length_, str.length());
+
+	text_ = str;
+	cursor_pos_ = str.length();
+	set_cursor(str.length());
+}
+
+void TextField::set_cursor(uint32_t pos) {
+	cursor_pos_ = std::min<size_t>(pos, text_.length());
+	set_dirty();
+}
+
+void TextField::set_max_length(size_t max_length) {
+	// Doesn't make sense, ignore.
+	if (max_length == 0)
+		return;
+
+	if (max_length < text_.length()) {
+		text_.erase(max_length - 1);
+		text_.shrink_to_fit();
+	} else {
+		text_.reserve(max_length);
+	}
+
+	max_length_ = max_length;
+	set_cursor(cursor_pos_);
+}
+
+void TextField::set_insert_mode() {
+	insert_mode_ = true;
+}
+
+void TextField::set_overwrite_mode() {
+	insert_mode_ = false;
+}
+
+void TextField::char_add(char c) {
+	// Don't add if inserting and at max_length and
+	// don't overwrite if past the end of the text.
+	if ((text_.length() >= max_length_ && insert_mode_) ||
+		(cursor_pos_ >= text_.length() && !insert_mode_))
+		return;
+
+	if (insert_mode_)
+		text_.insert(cursor_pos_, 1, c);
+	else
+		text_[cursor_pos_] = c;
+
+	cursor_pos_++;
+	set_dirty();
+}
+
+void TextField::char_delete() {
+	if (cursor_pos_ == 0)
+		return;
+
+	cursor_pos_--;
+	text_.erase(cursor_pos_, 1);
+	set_dirty();
+}
+
+void TextField::paint(Painter& painter) {
+	constexpr int char_width = 8;
+
+	auto rect = screen_rect();
+	auto text_style = has_focus() ? style().invert() : style();
+	auto offset = 0;
+
+	// Does the string need to be shifted?
+	if (cursor_pos_ >= char_count_)
+		offset = cursor_pos_ - char_count_ + 1;
+
+	// Clear the control.
+	painter.fill_rectangle(rect, text_style.background);
+
+	// Draw the text starting at the offset.
+	for (uint32_t i = 0; i < char_count_ && i + offset < text_.length(); i++) {
+		painter.draw_char(
+			{ rect.location().x() + (static_cast<int>(i) * char_width), rect.location().y() },
+			text_style,
+			text_[i + offset]
+		);
+	}
+
+	// Determine cursor position on screen (either the cursor position or the last char).
+	int32_t cursor_x = char_width * (offset > 0 ? char_count_ - 1 : cursor_pos_);
+	Point cursor_point{ screen_pos().x() + cursor_x, screen_pos().y() };
+	auto cursor_style = text_style.invert();
+
+	// Invert the cursor character when in overwrite mode.
+	if (!insert_mode_ && (cursor_pos_) < text_.length())
+		painter.draw_char(cursor_point, cursor_style, text_[cursor_pos_]);
+
+	// Draw the cursor.
+	Rect cursor_box{ cursor_point, { char_width, 16 } };
+	painter.draw_rectangle(cursor_box, cursor_style.background);
+}
+
+bool TextField::on_key(const KeyEvent key) {
+	if (key == KeyEvent::Left && cursor_pos_ > 0)
+		cursor_pos_--;
+	else if (key == KeyEvent::Right && cursor_pos_ < text_.length())
+		cursor_pos_++;
+	else if (key == KeyEvent::Select)
+		insert_mode_ = !insert_mode_;
+	else
+		return false;
+
+	set_dirty();
+	return true;
+}
+
+bool TextField::on_encoder(const EncoderEvent delta) {
+	int32_t new_pos = cursor_pos_ + delta;
+
+	// Let the encoder wrap around the ends of the text.
+	if (new_pos < 0)
+		new_pos = text_.length();
+	else if (static_cast<size_t>(new_pos) > text_.length())
+		new_pos = 0;
+
+	set_cursor(new_pos);
+	return true;
+}
+
+bool TextField::on_touch(const TouchEvent event) {
+	if (event.type == TouchEvent::Type::Start)
+		focus();
+
+	set_dirty();
+	return true;
+}
+
+/* TextEntryView ***********************************************************/
+
+void TextEntryView::char_delete() {
+	text_input.char_delete();
 }
 
 void TextEntryView::char_add(const char c) {
-	if (cursor_pos >= _max_length) return;
-	
-	_str += c;
-	cursor_pos++;
-}
-
-void TextEntryView::draw_cursor() {
-	Point draw_pos;
-	
-	draw_pos = { text_input.screen_rect().location().x() + std::min((Coord)cursor_pos, (Coord)28) * 8,
-					text_input.screen_rect().location().y() + 16 };
-	
-	// Erase previous
-	display.fill_rectangle(
-		{ { text_input.screen_rect().location().x(), draw_pos.y() }, { text_input.screen_rect().size().width(), 4 } },
-		Color::black()
-	);
-	// Draw new
-	display.fill_rectangle(
-		{ draw_pos, { 8, 4 } },
-		Color::white()
-	);
+	text_input.char_add(c);
 }
 
 void TextEntryView::focus() {
-	button_ok.focus();
+	text_input.focus();
 }
 
 TextEntryView::TextEntryView(
 	NavigationView& nav,
 	std::string& str,
 	size_t max_length
-) : _str(str),
-	_max_length(max_length)
+) : text_input{ str, max_length, { 0, 0 } }
 {
-	
-	// Trim from right
-	//_str->erase(std::find_if(_str->rbegin(), _str->rend(), std::not1(std::ptr_fun<int, int>(std::isspace))).base(), _str->end());
-	if (_str.length() > _max_length)
-		_str.resize(_max_length);
-	_str.reserve(_max_length);
-	
-	cursor_pos = _str.length();
-	
 	add_children({
 		&text_input,
 		&button_ok
 	});
 
-	button_ok.on_select = [this, &nav](Button&) {
-		_str.resize(cursor_pos);
+	button_ok.on_select = [this, &str, &nav](Button&) {
+		str.shrink_to_fit(); // NB: str is the TextField string.
 		if (on_changed)
-			on_changed(_str);
+			on_changed(str);
 		nav.pop();
 	};
 }

firmware/application/ui/ui_textentry.hpp

@@ -28,6 +28,54 @@
 
 namespace ui {
 
+// A TextField is bound to a string reference and allows the string
+// to be manipulated. The field itself does not provide the UI for
+// setting the value. It provides the UI of rendering the text,
+// a cursor, and an API to edit the string content.
+class TextField : public Widget {
+public:
+	TextField(std::string& str, Point position, uint32_t length = 30)
+		: TextField{str, 64, position, length} { }
+
+	// Str: the string containing the content to edit.
+	// Max_length: max length the string is allowed to use.
+	// Position: the top-left corner of the control.
+	// Length: the number of characters to display.
+	//   - Characters are 8 pixels wide.
+	//   - The screen can show 30 characters max.
+	//   - The control is 16 pixels tall.
+	TextField(std::string& str, size_t max_length, Point position, uint32_t length = 30);
+
+	TextField(const TextField&) = delete;
+	TextField(TextField&&) = delete;
+	TextField& operator=(const TextField&) = delete;
+	TextField& operator=(TextField&&) = delete;
+
+	const std::string& value() const;
+
+	void set(const std::string& str);
+	void set_cursor(uint32_t pos);
+	void set_max_length(size_t max_length);
+	void set_insert_mode();
+	void set_overwrite_mode();
+
+	void char_add(char c);
+	void char_delete();
+
+	void paint(Painter& painter) override;
+
+	bool on_key(const KeyEvent key) override;
+	bool on_encoder(const EncoderEvent delta) override;
+	bool on_touch(const TouchEvent event) override;
+
+protected:
+	std::string&   text_;
+	size_t         max_length_;
+	uint32_t       char_count_;
+	uint32_t       cursor_pos_;
+	bool           insert_mode_;
+};
+
 class TextEntryView : public View {
 public:
 	std::function<void(std::string&)> on_changed { };
@@ -45,17 +93,8 @@ protected:
 
 	void char_add(const char c);
 	void char_delete();
-	void draw_cursor();
-	void update_text();
-	
-	std::string& _str;
-	size_t _max_length;
-	uint32_t cursor_pos { 0 };
-	
-	Text text_input {
-		{ 0, 0, 240, 16 }
-	};
 	
+	TextField text_input;
 	Button button_ok {
 		{ 10 * 8, 33 * 8, 9 * 8, 32 },
 		"OK"

firmware/common/ui_painter.cpp

@@ -43,7 +43,7 @@ int Painter::draw_char(const Point p, const Style& style, const char c) {
 }
 
 int Painter::draw_string(Point p, const Font& font, const Color foreground,
-	const Color background, const std::string text) {
+	const Color background, const std::string& text) {
 	
 	bool escape = false;
 	size_t width = 0;
@@ -71,7 +71,7 @@ int Painter::draw_string(Point p, const Font& font, const Color foreground,
 	return width;
 }
 
-int Painter::draw_string(Point p, const Style& style, const std::string text) {
+int Painter::draw_string(Point p, const Style& style, const std::string& text) {
 	return draw_string(p, style.font, style.foreground, style.background, text);
 }
 

firmware/common/ui_painter.hpp

@@ -49,8 +49,8 @@ public:
 	int draw_char(const Point p, const Style& style, const char c);
 
 	int draw_string(Point p, const Font& font, const Color foreground,
-		const Color background, const std::string text);
-	int draw_string(Point p, const Style& style, const std::string text);
+		const Color background, const std::string& text);
+	int draw_string(Point p, const Style& style, const std::string& text);
 
 	void draw_bitmap(const Point p, const Bitmap& bitmap, const Color background, const Color foreground);