Menu fallbacks for EGA/VGA terminal.

rerdavies · rerdavies · commit 65ec90315778 · 2025-02-02T19:35:14.000-05:00
diff --git a/ReleaseNotes.md b/ReleaseNotes.md
@@ -1,5 +1,12 @@
 ## Release Notes
 
+### NWindows 0.0.2-beta1
+
+- Polyfill checkbox/radio-button/dropdon characters on EGA/VGA (Linux) terminals.
+- can_display_character tests display font on Linux EGA/VGA terminals.
+- Fallback to ASCII for particularly incapable terminals.
+
+
 ### NWindows 0.0.1-beta1
 
 Initial release of the NWindows Library.
diff --git a/examples/nwindows_test/ascii_fallback_test_window.cpp b/examples/nwindows_test/ascii_fallback_test_window.cpp
@@ -73,20 +73,12 @@ class NCharacterTestWindow: public NElement {
         return { 2,1 };
     }
     virtual void render() override {
-        cchar_t ch;
-        memset(&ch,0,sizeof(ch));
-        ch.chars[0] = this->c;
-        ch.chars[1] = 0;
-
-        bool valid = wadd_wch(stdscr,&ch) != ERR;
+        bool valid = window()->can_display_character(this->c);
         move(0,0);
         wchar_t str[2] = {this->c,0};
         if (!valid) {
             str[0] = L'X';
         }
-        if (ch.chars[0] != this->c) {
-            str[0] = L'?';
-        }
         print(str);
     }
 private:
@@ -184,7 +176,7 @@ void ascii_fallback_test_window(NWindow::ptr parentWindow /* = nullptr */)
             | margin({ 2,1,2,1 })
             | row_gap(1)
             | add_child(
-                NTextElement::create("Fallbacks only occur on non-Unicode terminals. ◉●○🗹□☑☐")
+                NTextElement::create("Fallbacks only occur on non-Unicode terminals. ●○ ☑☐ ⏵⏷ ◉🗹□")
                 | wrap_text()
             )
             | add_child(
diff --git a/src/ConsoleFontTest.cpp b/src/ConsoleFontTest.cpp
@@ -56,7 +56,7 @@ void test_font(
             << " characters: " << font->character_count()
             << " map: " << (font->has_unicode_map() ? "yes" : "no")
             << " extra: " << (font->extra_bytes());
-        std::u32string sacrificialCharacters = ::nwindows::internal::get_sacrificial_characters(font, 4);
+        std::u32string sacrificialCharacters = ::nwindows::internal::get_sacrificial_characters(font, 6);
         std::cout << " sac: " << u32string_to_utf8(sacrificialCharacters) << std::endl; 
 
         std::cout << std::endl;
diff --git a/src/NWindows.cpp b/src/NWindows.cpp
@@ -790,8 +790,24 @@ void NWindow::close()
 
         if (curses_window_)
         {
+
+
+            try {
+                // eliminate red color flash as palette changes during shutdown.
+                if (color_palette_->DesktopBackground != color_palette_->Black) {
+                    if (max_colors_ > 8) {
+                        auto defaultColor = make_color_pair(color_palette_->White, color_palette_->Black);
+                        wbkgd(root_curses_window_, defaultColor.attribute());
+                    }
+                }
+            }
+            catch (const std::exception& ignore)
+            {
+                (void)ignore; // ran out of colors? ignore.
+            }
+
             clear_window();
-            //q restore_colors();
+
             del_panel(curses_panel_);
             delwin(curses_window_);
 
@@ -1320,8 +1336,10 @@ void NWindow::init_root_window()
         init_color(COLOR_WHITE, color_palette_->White);
 
         if (color_palette_->DesktopBackground != color_palette_->Black) {
-            auto desktopColor = make_color_pair(color_palette_->DesktopBackground, color_palette_->DesktopBackground);
-            wbkgd(root_curses_window_, desktopColor.attribute());
+            if (max_colors_ > 8) {
+                auto desktopColor = make_color_pair(color_palette_->DesktopBackground, color_palette_->DesktopBackground);
+                wbkgd(root_curses_window_, desktopColor.attribute());
+            }
         }
 
 
@@ -4630,7 +4648,7 @@ std::string NCheckboxElement::unchecked_text() const
     {
         if (window()->console_font())
         {
-           return " ☐  "; // u2610
+            return " ☐  "; // u2610
         }
         if (use_raspberry_pi_fallback() && (!window()->console_font()))
         {
@@ -5742,22 +5760,22 @@ void NPopupMenuWindow::handle_cancelled()
 static const std::string CHECKMARK_PREFIX = " ✓ ";
 static const std::string ASCII_CHECKMARK_PREFIX = " X ";
 
-static std::string checkmark_prefix(bool is_unicode) {
-    if (is_unicode)
+static std::string checkmark_prefix(NWindow* window) {
+    if (window->can_display_character(L'✓'))
     {
         return CHECKMARK_PREFIX;
     }
     return ASCII_CHECKMARK_PREFIX;
 }
-int NPopupMenuWindow::measure_prefix(const NMenuItem& item, bool is_unicode_locale)
+int NPopupMenuWindow::measure_prefix(std::shared_ptr<NWindow> window, const NMenuItem& menuItem)
 {
-    if (item.display_check)
+    if (menuItem.display_check)
     {
-        return this->measure_text(checkmark_prefix(is_unicode_locale));
+        return measure_text(checkmark_prefix(this));
     }
-    else if (item.icon.length() != 0)
+    else if (menuItem.icon.length() != 0)
     {
-        return this->measure_text(item.icon) + 2;
+        return measure_text(menuItem.icon) + 2;
     }
     else {
         return 1;
@@ -5782,7 +5800,7 @@ void NPopupMenuWindow::Init(NWindow::ptr parentWindow, const std::vector<NMenuIt
 
     int prefixWidth = 0;
     for (auto& item : menu_items) {
-        prefixWidth = std::max(prefixWidth, measure_prefix(item, parentWindow->is_unicode_locale()));
+        prefixWidth = std::max(prefixWidth, measure_prefix(parentWindow, item));
     }
 
     for (auto& item : menu_items)
@@ -5838,7 +5856,7 @@ void NPopupMenuWindow::Init(NWindow::ptr parentWindow, const std::vector<NMenuIt
             if (item.display_check) {
                 if (item.checked)
                 {
-                    prefix = checkmark_prefix(parentWindow->is_unicode_locale());
+                    prefix = checkmark_prefix(parentWindow.get());
                 }
             }
             else if (item.icon.length() != 0)
@@ -5947,9 +5965,9 @@ void NSubmenuMenuItemElement::open(bool value)
                     if (this_)
                     {
                         this_->on_cancelled.fire(this_);
+                        this_->popup_window_ = nullptr; // don't call close()
+                        this_->open(false);
                     }
-                    this_->popup_window_ = nullptr; // don't call close()
-                    this_->open(false);
                 }
             );
         }
@@ -5969,7 +5987,7 @@ void NSubmenuMenuItemElement::open(bool value)
 void NSubmenuMenuItemElement::handle_attached(NWindow* window)
 {
     super::handle_attached(window);
-    if (window->is_unicode_locale())
+    if (window->can_display_character(L'⏵'))
     {
         this->suffix(" ⏵ ");
     }
@@ -6200,23 +6218,24 @@ NMessageWindow::ptr NMessageWindow::create(
 
 void NMessageWindow::init(NWindow::ptr parent_window, NMessageType message_type, const std::string& message, int text_block_width)
 {
-    if (parent_window->is_unicode_locale())
+    std::string iconText;
+
+    switch (message_type)
     {
-        // with an icon.
-        std::string iconText;
+    case NMessageType::Error:
+        iconText = "🛑︎\uFE0E"; // (\uFe0E = display b&w variant)
+        break;
+    case NMessageType::Warning:
+        iconText = "⚠️";
+        break;
+    case NMessageType::Info:
+        iconText = "🛈";
+        break;
+    }
 
-        switch (message_type)
-        {
-        case NMessageType::Error:
-            iconText = "🛑︎\uFE0E"; // (\uFe0E = display b&w variant)
-            break;
-        case NMessageType::Warning:
-            iconText = "⚠️";
-            break;
-        case NMessageType::Info:
-            iconText = "🛈";
-            break;
-        }
+    if (parent_window->can_display_character(utf8_char32_at(iconText,0)))
+    {
+        // with an icon.
 
         this->add_child(
             NVerticalStackElement::create()
diff --git a/src/SyntheticCharacters.cpp b/src/SyntheticCharacters.cpp
@@ -466,6 +466,36 @@ static std::vector<uint8_t> make_dropdown(
     }
     return bitmap.data();
 }
+static std::vector<uint8_t> make_flyout(
+    const std::vector<uint8_t>& copyrData,
+    size_t char_width,
+    size_t char_height)
+{
+    MonoBitmap bitmap(copyrData, char_width, char_height);
+    CopyrightDimensions info = get_copyright_dimensions(bitmap);
+
+    bitmap.clear();
+
+    int cx = (info.outer.left()*2 + info.outer.right())/3;
+    int cy = (info.outer.top() + info.outer.bottom())/2;
+    for (int ix = 0; ix < (int)char_width; ++ix)
+    {
+        if (ix >= cx) 
+        {
+            int x0 = ix-cx;
+            x0 = info.outer.width/2-x0;
+            int top0 = std::max(0,cy-x0);
+            int top1 = std::min((int)char_height,cy + x0);
+
+            for (int iy = top0; iy < top1; ++iy)
+            {
+                bitmap.set(ix,iy,true);
+            }
+        }
+    }
+    return bitmap.data();
+}
+
 static std::vector<uint8_t> make_radio_button_unchecked(
     const std::vector<uint8_t>& copyrData,
     size_t char_width,
@@ -528,9 +558,10 @@ void ::nwindows::internal::add_synthetic_characters(ConsoleFont::ptr font)
     char32_t CHECKBOX_CHECKED_CHAR = L'\u2611'; // ☑
     char32_t CHECKBOX_UNCHECKED_CHAR = L'\u2610'; //☐
     char32_t DROPDOWN_CHAR = L'⏷'; // ⏷
+    char32_t FLYOUT_CHAR = L'⏵'; // ⏵
 
 
-    auto sacrificial_characters = get_sacrificial_characters(font, 5);
+    auto sacrificial_characters = get_sacrificial_characters(font, 6);
 
     // use copyright symbol as a template for constructing the new characters.
     size_t copyrIndex = font->get_glyph_position(U'\u00A9').value();
@@ -541,12 +572,14 @@ void ::nwindows::internal::add_synthetic_characters(ConsoleFont::ptr font)
     auto checkboxChecked = make_checkbox_checked(copyrData, font->char_width(), font->char_height());
     auto checkboxUnchecked = make_checkbox_unchecked(copyrData, font->char_width(), font->char_height());
     auto dropdown = make_dropdown(copyrData, font->char_width(), font->char_height());
+    auto flyout = make_flyout(copyrData, font->char_width(), font->char_height());
 
     replace_character(font, sacrificial_characters[0], RADIO_BUTTON_CHECKED_CHAR, radioButtonChecked);
     replace_character(font, sacrificial_characters[1], RADIO_BUTTON_UNCHECKED_CHAR, radioButtonUnchecked);
     replace_character(font, sacrificial_characters[2], CHECKBOX_CHECKED_CHAR, checkboxChecked);
     replace_character(font, sacrificial_characters[3], CHECKBOX_UNCHECKED_CHAR, checkboxUnchecked);
     replace_character(font, sacrificial_characters[4], DROPDOWN_CHAR, dropdown);
+    replace_character(font, sacrificial_characters[5], FLYOUT_CHAR, flyout);
 }
 
 
diff --git a/src/include/NWindows/NWindows.hpp b/src/include/NWindows/NWindows.hpp
@@ -1424,7 +1424,6 @@ namespace nwindows
 
         // same locale string as std::setlocale
         static void set_locale(const std::string& locale);
-        bool is_unicode_locale() const { return is_unicode_locale_; }
         bool can_display_character(char32_t c) const;
 
         std::shared_ptr<ConsoleFont> console_font() const { return this->top_level_window()->console_font_; } 
@@ -1616,6 +1615,9 @@ namespace nwindows
         virtual void render() override;
 
     private:
+
+        bool is_unicode_locale() const { return is_unicode_locale_; }
+
         std::shared_ptr<internal::ConsoleFontManager> console_font_manager_;
 
         std::string fatal_error_message_;
@@ -1946,7 +1948,7 @@ namespace nwindows
         virtual void handle_cancelled();
 
     private:
-        int measure_prefix(const NMenuItem& menuItem, bool isUnicodeLocale);
+        int measure_prefix(std::shared_ptr<NWindow> window, const NMenuItem& menuItem);
         bool was_item_selected_ = false;
 
     };

Original file line number	Diff line number	Diff line change
`@@ -790,8 +790,24 @@ void NWindow::close()`
`790`	`790`
`791`	`791`	`if (curses_window_)`
`792`	`792`	`{`
	`793`	`+`
	`794`	`+`
	`795`	`+ try {`
	`796`	`+ // eliminate red color flash as palette changes during shutdown.`
	`797`	`+ if (color_palette_->DesktopBackground != color_palette_->Black) {`
	`798`	`+ if (max_colors_ > 8) {`
	`799`	`+ auto defaultColor = make_color_pair(color_palette_->White, color_palette_->Black);`
	`800`	`+ wbkgd(root_curses_window_, defaultColor.attribute());`
	`801`	`+ }`
	`802`	`+ }`
	`803`	`+ }`
	`804`	`+ catch (const std::exception& ignore)`
	`805`	`+ {`
	`806`	`+ (void)ignore; // ran out of colors? ignore.`
	`807`	`+ }`
	`808`	`+`
`793`	`809`	`clear_window();`
`794`		`- //q restore_colors();`
	`810`	`+`
`795`	`811`	`del_panel(curses_panel_);`
`796`	`812`	`delwin(curses_window_);`
`797`	`813`
`@@ -1320,8 +1336,10 @@ void NWindow::init_root_window()`
`1320`	`1336`	`init_color(COLOR_WHITE, color_palette_->White);`
`1321`	`1337`
`1322`	`1338`	`if (color_palette_->DesktopBackground != color_palette_->Black) {`
`1323`		`- auto desktopColor = make_color_pair(color_palette_->DesktopBackground, color_palette_->DesktopBackground);`
`1324`		`- wbkgd(root_curses_window_, desktopColor.attribute());`
	`1339`	`+ if (max_colors_ > 8) {`
	`1340`	`+ auto desktopColor = make_color_pair(color_palette_->DesktopBackground, color_palette_->DesktopBackground);`
	`1341`	`+ wbkgd(root_curses_window_, desktopColor.attribute());`
	`1342`	`+ }`
`1325`	`1343`	`}`
`1326`	`1344`
`1327`	`1345`
`@@ -4630,7 +4648,7 @@ std::string NCheckboxElement::unchecked_text() const`
`4630`	`4648`	`{`
`4631`	`4649`	`if (window()->console_font())`
`4632`	`4650`	`{`
`4633`		`- return " ☐ "; // u2610`
	`4651`	`+ return " ☐ "; // u2610`
`4634`	`4652`	`}`
`4635`	`4653`	`if (use_raspberry_pi_fallback() && (!window()->console_font()))`
`4636`	`4654`	`{`
`@@ -5742,22 +5760,22 @@ void NPopupMenuWindow::handle_cancelled()`
`5742`	`5760`	`static const std::string CHECKMARK_PREFIX = " ✓ ";`
`5743`	`5761`	`static const std::string ASCII_CHECKMARK_PREFIX = " X ";`
`5744`	`5762`
`5745`		`-static std::string checkmark_prefix(bool is_unicode) {`
`5746`		`- if (is_unicode)`
	`5763`	`+static std::string checkmark_prefix(NWindow* window) {`
	`5764`	`+ if (window->can_display_character(L'✓'))`
`5747`	`5765`	`{`
`5748`	`5766`	`return CHECKMARK_PREFIX;`
`5749`	`5767`	`}`
`5750`	`5768`	`return ASCII_CHECKMARK_PREFIX;`
`5751`	`5769`	`}`
`5752`		`-int NPopupMenuWindow::measure_prefix(const NMenuItem& item, bool is_unicode_locale)`
	`5770`	`+int NPopupMenuWindow::measure_prefix(std::shared_ptr<NWindow> window, const NMenuItem& menuItem)`
`5753`	`5771`	`{`
`5754`		`- if (item.display_check)`
	`5772`	`+ if (menuItem.display_check)`
`5755`	`5773`	`{`
`5756`		`- return this->measure_text(checkmark_prefix(is_unicode_locale));`
	`5774`	`+ return measure_text(checkmark_prefix(this));`
`5757`	`5775`	`}`
`5758`		`- else if (item.icon.length() != 0)`
	`5776`	`+ else if (menuItem.icon.length() != 0)`
`5759`	`5777`	`{`
`5760`		`- return this->measure_text(item.icon) + 2;`
	`5778`	`+ return measure_text(menuItem.icon) + 2;`
`5761`	`5779`	`}`
`5762`	`5780`	`else {`
`5763`	`5781`	`return 1;`
`@@ -5782,7 +5800,7 @@ void NPopupMenuWindow::Init(NWindow::ptr parentWindow, const std::vector<NMenuIt`
`5782`	`5800`
`5783`	`5801`	`int prefixWidth = 0;`
`5784`	`5802`	`for (auto& item : menu_items) {`
`5785`		`- prefixWidth = std::max(prefixWidth, measure_prefix(item, parentWindow->is_unicode_locale()));`
	`5803`	`+ prefixWidth = std::max(prefixWidth, measure_prefix(parentWindow, item));`
`5786`	`5804`	`}`
`5787`	`5805`
`5788`	`5806`	`for (auto& item : menu_items)`
`@@ -5838,7 +5856,7 @@ void NPopupMenuWindow::Init(NWindow::ptr parentWindow, const std::vector<NMenuIt`
`5838`	`5856`	`if (item.display_check) {`
`5839`	`5857`	`if (item.checked)`
`5840`	`5858`	`{`
`5841`		`- prefix = checkmark_prefix(parentWindow->is_unicode_locale());`
	`5859`	`+ prefix = checkmark_prefix(parentWindow.get());`
`5842`	`5860`	`}`
`5843`	`5861`	`}`
`5844`	`5862`	`else if (item.icon.length() != 0)`
`@@ -5947,9 +5965,9 @@ void NSubmenuMenuItemElement::open(bool value)`
`5947`	`5965`	`if (this_)`
`5948`	`5966`	`{`
`5949`	`5967`	`this_->on_cancelled.fire(this_);`
	`5968`	`+ this_->popup_window_ = nullptr; // don't call close()`
	`5969`	`+ this_->open(false);`
`5950`	`5970`	`}`
`5951`		`- this_->popup_window_ = nullptr; // don't call close()`
`5952`		`- this_->open(false);`
`5953`	`5971`	`}`
`5954`	`5972`	`);`
`5955`	`5973`	`}`
`@@ -5969,7 +5987,7 @@ void NSubmenuMenuItemElement::open(bool value)`
`5969`	`5987`	`void NSubmenuMenuItemElement::handle_attached(NWindow* window)`
`5970`	`5988`	`{`
`5971`	`5989`	`super::handle_attached(window);`
`5972`		`- if (window->is_unicode_locale())`
	`5990`	`+ if (window->can_display_character(L'⏵'))`
`5973`	`5991`	`{`
`5974`	`5992`	`this->suffix(" ⏵ ");`
`5975`	`5993`	`}`
`@@ -6200,23 +6218,24 @@ NMessageWindow::ptr NMessageWindow::create(`
`6200`	`6218`
`6201`	`6219`	`void NMessageWindow::init(NWindow::ptr parent_window, NMessageType message_type, const std::string& message, int text_block_width)`
`6202`	`6220`	`{`
`6203`		`- if (parent_window->is_unicode_locale())`
	`6221`	`+ std::string iconText;`
	`6222`	`+`
	`6223`	`+ switch (message_type)`
`6204`	`6224`	`{`
`6205`		`- // with an icon.`
`6206`		`- std::string iconText;`
	`6225`	`+ case NMessageType::Error:`
	`6226`	`+ iconText = "🛑︎\uFE0E"; // (\uFe0E = display b&w variant)`
	`6227`	`+ break;`
	`6228`	`+ case NMessageType::Warning:`
	`6229`	`+ iconText = "⚠️";`
	`6230`	`+ break;`
	`6231`	`+ case NMessageType::Info:`
	`6232`	`+ iconText = "🛈";`
	`6233`	`+ break;`
	`6234`	`+ }`
`6207`	`6235`
`6208`		`- switch (message_type)`
`6209`		`- {`
`6210`		`- case NMessageType::Error:`
`6211`		`- iconText = "🛑︎\uFE0E"; // (\uFe0E = display b&w variant)`
`6212`		`- break;`
`6213`		`- case NMessageType::Warning:`
`6214`		`- iconText = "⚠️";`
`6215`		`- break;`
`6216`		`- case NMessageType::Info:`
`6217`		`- iconText = "🛈";`
`6218`		`- break;`
`6219`		`- }`
	`6236`	`+ if (parent_window->can_display_character(utf8_char32_at(iconText,0)))`
	`6237`	`+ {`
	`6238`	`+ // with an icon.`
`6220`	`6239`
`6221`	`6240`	`this->add_child(`
`6222`	`6241`	`NVerticalStackElement::create()`