From 941156a291bdabfc9e6af685ef77d1a72873484a Mon Sep 17 00:00:00 2001
From: 0xFEEDC0DE64 <daniel@brunner.ninja>
Date: Sun, 5 Sep 2021 19:16:46 +0200
Subject: [PATCH] Implemented rich text rendering

---
 CMakeLists.txt           |   2 +
 src/richtextrenderer.cpp | 129 +++++++++++++++++++++++++++++++++++++++
 src/richtextrenderer.h   |  18 ++++++
 src/widgets/label.cpp    |   3 +-
 4 files changed, 151 insertions(+), 1 deletion(-)
 create mode 100644 src/richtextrenderer.cpp
 create mode 100644 src/richtextrenderer.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 53864b4..f9598f5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -13,6 +13,7 @@ set(headers
     src/iconinterface.h
     src/menudisplay.h
     src/menuitem.h
+    src/richtextrenderer.h
     src/screenmanager.h
     src/tftinstance.h
     src/textinterface.h
@@ -39,6 +40,7 @@ set(sources
     src/changevaluedisplay_sntp_sync_mode_t.cpp
     src/menudisplay.cpp
     src/screenmanager.cpp
+    src/richtextrenderer.cpp
     src/tftinstance.cpp
     src/icons/back.cpp
     src/icons/checked.cpp
diff --git a/src/richtextrenderer.cpp b/src/richtextrenderer.cpp
new file mode 100644
index 0000000..5224948
--- /dev/null
+++ b/src/richtextrenderer.cpp
@@ -0,0 +1,129 @@
+#include "richtextrenderer.h"
+
+// system includes
+#include <string_view>
+
+// 3rdparty lib includes
+#include <strutils.h>
+
+namespace espgui {
+
+void richTextEscape(std::string &subject)
+{
+    cpputils::stringReplaceAll('&', "&&", subject);
+}
+
+std::string richTextEscape(std::string_view subject)
+{
+    return cpputils::stringReplaceAll('&', "&&", subject);
+}
+
+int16_t renderRichText(std::string_view str, int32_t poX, int32_t poY)
+{
+    return renderRichText(str, poX, poY, tft.textfont);
+}
+
+int16_t renderRichText(std::string_view str, int32_t poX, int32_t poY, uint8_t font)
+{
+    if (str.empty())
+        return 0;
+
+    const auto oldColor = tft.textcolor;
+
+    int16_t width{};
+
+again:
+    if (const auto index = str.find('&'); index != std::string_view::npos)
+    {
+        {
+            std::string_view tempStr{std::begin(str), index};
+            if (!tempStr.empty())
+            {
+                const auto addedWith = tft.drawString(tempStr, poX, poY, font);
+                poX += addedWith;
+                width += addedWith;
+            }
+        }
+
+        auto newIter = std::begin(str) + index + 1;
+        if (newIter != std::end(str))
+        {
+            switch (const auto controlChar = *newIter)
+            {
+            case '0':
+            case '1':
+            case '2':
+            {
+                const auto color = [&controlChar](){
+                    switch (controlChar)
+                    {
+                    case '0': return TFT_RED;
+                    case '1': return TFT_GREEN;
+                    case '2': return TFT_BLUE;
+                    }
+                    __builtin_unreachable();
+                }();
+
+                tft.setTextColor(color, tft.textbgcolor);
+
+                auto newNewIter = newIter + 1;
+                if (newNewIter != std::end(str))
+                {
+                    str = std::string_view(newNewIter, std::distance(newNewIter, std::end(str)));
+                    goto again;
+                }
+                break;
+            }
+//            case '&':
+//            {
+//                const char buf[1] = { '&' };
+//                const auto addedWith = tft.drawString(std::string_view{buf, std::size(buf)}, poX, poY, font);
+//                poX += addedWith;
+//                width += addedWith;
+
+//                auto newNewIter = newIter + 1;
+//                if (newNewIter != std::end(str))
+//                {
+//                    str = std::string_view(newNewIter, std::distance(newNewIter, std::end(str)));
+//                    goto again;
+//                }
+//                break;
+//            }
+            default:
+            {
+                const char buf[2] = { '&', controlChar };
+                const auto addedWith = tft.drawString(std::string_view{buf, std::size(buf)}, poX, poY, font);
+                poX += addedWith;
+                width += addedWith;
+
+                auto newNewIter = newIter + 1;
+                if (newNewIter != std::end(str))
+                {
+                    str = std::string_view(newNewIter, std::distance(newNewIter, std::end(str)));
+                    goto again;
+                }
+                break;
+            }
+            }
+        }
+        else
+        {
+            const char buf[1] = { '&' };
+            const auto addedWith = tft.drawString(std::string_view{buf, std::size(buf)}, poX, poY, font);
+            poX += addedWith;
+            width += addedWith;
+        }
+    }
+    else if (!str.empty())
+    {
+        const auto addedWith = tft.drawString(str, poX, poY, font);
+        poX += addedWith;
+        width += addedWith;
+    }
+
+    tft.setTextColor(oldColor, tft.textbgcolor);
+
+    return width;
+}
+
+} // namespace espgui
diff --git a/src/richtextrenderer.h b/src/richtextrenderer.h
new file mode 100644
index 0000000..5d36b36
--- /dev/null
+++ b/src/richtextrenderer.h
@@ -0,0 +1,18 @@
+#pragma once
+
+// system includes
+#include <string_view>
+#include <string>
+
+// local includes
+#include "tftinstance.h"
+
+namespace espgui {
+
+void richTextEscape(std::string &subject);
+std::string richTextEscape(std::string_view subject);
+
+int16_t renderRichText(std::string_view str, int32_t poX, int32_t poY);
+int16_t renderRichText(std::string_view str, int32_t poX, int32_t poY, uint8_t font);
+
+} // namespace espgui
diff --git a/src/widgets/label.cpp b/src/widgets/label.cpp
index d0c11a2..cf0ed0f 100644
--- a/src/widgets/label.cpp
+++ b/src/widgets/label.cpp
@@ -2,6 +2,7 @@
 
 // local includes
 #include "tftinstance.h"
+#include "richtextrenderer.h"
 
 namespace espgui {
 Label::Label(int x, int y) :
@@ -28,7 +29,7 @@ void Label::redraw(std::string_view str, bool forceRedraw)
         !forceRedraw)
         return;
 
-    const auto renderedWidth = str.empty() ? 0 : tft.drawString(str.data(), m_x, m_y);
+    const auto renderedWidth = renderRichText(str, m_x, m_y);
     const auto renderedHeight = tft.fontHeight();
 
     if (renderedWidth < m_lastWidth)