Make dchat Text editable

Not finished yet. Currently text can be entered, removed and you can move caret
using arrow keys (up, down, left, right), home and end.
Need to implement text selection and remove focus from chatbar when
editing message board text.
Chatbar should be replaced with dchat Text for proper multiline editable
text.

6 files changed, 346 insertions, 35 deletions

diff --git a/src/Cache.cpp b/src/Cache.cpp
index cba346b..c795595 100644
--- a/src/Cache.cpp
+++ b/src/Cache.cpp
@@ -196,22 +196,32 @@ namespace dchat
                     int exitStatus;
                     if(it->process->try_get_exit_status(exitStatus))
                     {
+                        ContentByUrlResult contentByUrlResult;
                         bool failed = exitStatus != 0;
-                        if(!failed)
+                        if(failed)
+                        {
+                            contentByUrlResult = { (sf::Texture*)nullptr, ContentByUrlResult::Type::FAILED_DOWNLOAD };
+                        }
+                        else
                         {
                             boost::filesystem::path filepath = getImagesDir();
                             odhtdb::Hash urlHash(it->url.data(), it->url.size());
                             filepath /= urlHash.toString();
                             
-                            ContentByUrlResult contentByUrlResult = loadImageFromFile(filepath);
-                            imageDownloadMutex.lock();
-                            contentUrlCache[it->url] = contentByUrlResult;
-                            imageDownloadMutex.unlock();
+                            contentByUrlResult = loadImageFromFile(filepath);
                             if(contentByUrlResult.type == ContentByUrlResult::Type::CACHED)
                             {
                                 printf("Download content from url: %s\n", it->url.c_str());
                             }
                         }
+                        
+                        imageDownloadMutex.lock();
+                        contentUrlCache[it->url] = contentByUrlResult;
+                        boost::filesystem::path downloadingFilepath = getImagesDir() / ".downloading";
+                        // Intentionally ignore failure, program should not crash if we fail to remove these files...
+                        boost::system::error_code err;
+                        boost::filesystem::remove(downloadingFilepath, err);
+                        imageDownloadMutex.unlock();
                         it = imageDownloadProcesses.erase(it);
                     }
                     else
@@ -243,6 +253,18 @@ namespace dchat
         downloadWaitThread.join();
     }
     
+    void replaceFileIgnoreError(const boost::filesystem::path &path)
+    {
+        try
+        {
+            fileReplace(path, StringView());
+        }
+        catch(FileException &e)
+        {
+            fprintf(stderr, "Failed to replace file: %s, reason: %s\n", path.string().c_str(), e.what());
+        }
+    }
+    
     const ContentByUrlResult Cache::getContentByUrl(const string &url, int downloadLimitBytes)
     {
         lock_guard<mutex> lock(imageDownloadMutex);
@@ -255,6 +277,15 @@ namespace dchat
         odhtdb::Hash urlHash(url.data(), url.size());
         filepath /= urlHash.toString();
         
+        boost::filesystem::path downloadingFilepath = getImagesDir() / ".downloading";
+        if(boost::filesystem::exists(downloadingFilepath))
+        {
+            // Intentionally ignore failure, program should not crash if we fail to remove these files...
+            boost::system::error_code err;
+            boost::filesystem::remove(filepath, err);
+            boost::filesystem::remove(downloadingFilepath, err);
+        }
+        
         ContentByUrlResult contentByUrlResult = loadImageFromFile(filepath);
         if(contentByUrlResult.type == ContentByUrlResult::Type::CACHED)
         {
@@ -268,6 +299,7 @@ namespace dchat
             return contentByUrlResult;
         }
         
+        replaceFileIgnoreError(downloadingFilepath);
         ContentByUrlResult result((sf::Texture*)nullptr, ContentByUrlResult::Type::DOWNLOADING);
         contentUrlCache[url] = result;
         
diff --git a/src/Channel.cpp b/src/Channel.cpp
index f8e79c6..2bd1b0b 100644
--- a/src/Channel.cpp
+++ b/src/Channel.cpp
@@ -31,6 +31,7 @@ namespace dchat
         
         {
             Message *message = new Message(&systemUser, u8"pepedab https://discordemoji.com/assets/emoji/PepeDab.gif coggers https://discordemoji.com/assets/emoji/COGGERS.gif check out this url http://www.grandtournation.com/6808/start-date-of-the-grand-tour-season-3-confirmed-mark-your-calendars/ owo");
+            message->text.setEditable(true);
             messageBoard.addMessage(message);
         }
         
diff --git a/src/ChannelSidePanel.cpp b/src/ChannelSidePanel.cpp
index 8d0b714..89a550a 100644
--- a/src/ChannelSidePanel.cpp
+++ b/src/ChannelSidePanel.cpp
@@ -33,7 +33,7 @@ namespace dchat
     {
         float posY = ChannelTopPanel::getHeight();
         auto windowSize = window.getSize();
-        sf::RectangleShape rect(sf::Vector2f(getWidth(), windowSize.y));
+        sf::RectangleShape rect(sf::Vector2f(getWidth(), windowSize.y - ChannelTopPanel::getHeight()));
         rect.setPosition(0.0f, posY);
         rect.setFillColor(ColorScheme::getPanelColor());
         window.draw(rect);
@@ -68,6 +68,6 @@ namespace dchat
     
     float ChannelSidePanel::getWidth()
     {
-        return WIDTH * Settings::getScaling();
+        return floor(WIDTH * Settings::getScaling());
     }
 }
diff --git a/src/MessageBoard.cpp b/src/MessageBoard.cpp
index cee3e50..d73dc84 100644
--- a/src/MessageBoard.cpp
+++ b/src/MessageBoard.cpp
@@ -238,6 +238,11 @@ namespace dchat
             selectingTextStart.x = mousePos.x;
             selectingTextStart.y = mousePos.y;
         }
+        
+        for(Message *message : messages)
+        {
+            message->text.processEvent(event);
+        }
     }
     
     void MessageBoard::draw(sf::RenderWindow &window, Cache &cache)
diff --git a/src/Text.cpp b/src/Text.cpp
index bc23235..be147db 100644
--- a/src/Text.cpp
+++ b/src/Text.cpp
@@ -22,8 +22,13 @@ namespace dchat
         color(sf::Color::White),
         urlColor(URL_COLOR),
         dirty(false),
+        dirtyText(false),
+        dirtyCaret(false),
         plainText(false),
-        totalHeight(0.0f)
+        editable(false),
+        caretMoveDirection(CaretMoveDirection::NONE),
+        totalHeight(0.0f),
+        caretIndex(0)
     {
         
     }
@@ -36,32 +41,28 @@ namespace dchat
         color(sf::Color::White),
         urlColor(URL_COLOR),
         dirty(true),
+        dirtyText(false),
+        dirtyCaret(false),
         plainText(_plainText),
+        editable(false),
+        caretMoveDirection(CaretMoveDirection::NONE),
         totalHeight(0.0f),
-        lineSpacing(0.0f)
+        lineSpacing(0.0f),
+        caretIndex(0)
     {
         setString(_str);
     }
+    
     void Text::setString(const sf::String &str)
     {
         if(str != this->str)
         {
             this->str = str;
             dirty = true;
-            textElements.clear();
-            stringSplitElements(this->str, 0);
+            dirtyText = true;
         }
     }
     
-    void Text::appendStringNewLine(const sf::String &str)
-    {
-        usize prevSize = this->str.getSize();
-        this->str += '\n';
-        this->str += str;
-        dirty = true;
-        stringSplitElements(this->str, prevSize);
-    }
-    
     void Text::setPosition(float x, float y)
     {
         position.x = x;
@@ -109,6 +110,20 @@ namespace dchat
         }
     }
     
+    void Text::setEditable(bool editable)
+    {
+        if(editable != this->editable)
+        {
+            this->editable = editable;
+            if(!plainText)
+            {
+                dirty = true;
+                dirtyText = true;
+            }
+            dirtyCaret = true;
+        }
+    }
+    
     float Text::getHeight() const
     {
         return totalHeight;
@@ -142,7 +157,7 @@ namespace dchat
     {
         StringViewUtf32 wholeStr(&stringToSplit[startIndex], stringToSplit.getSize() - startIndex);
         textElements.push_back({ wholeStr, TextElement::Type::TEXT });
-        if(plainText)
+        if(plainText || editable)
             return;
         
         const char *httpStrRaw = "http://";
@@ -159,9 +174,9 @@ namespace dchat
         static_assert(sizeof(*parentheseStr.getData()) == sizeof(u32), "sf::String size has changed...");
         
         std::vector<TextElement> newTextElements;
-        for(size_t i = 0; i < textElements.size(); ++i)
+        // Split emoji
+        for(const TextElement &textElement : textElements)
         {
-            TextElement textElement = textElements[i];
             if(textElement.type != TextElement::Type::TEXT)
             {
                 newTextElements.push_back(textElement);
@@ -199,10 +214,10 @@ namespace dchat
         }
         textElements = newTextElements;
         
+        // Split http
         newTextElements.clear();
-        for(size_t i = 0; i < textElements.size(); ++i)
+        for(const TextElement &textElement : textElements)
         {
-            TextElement textElement = textElements[i];
             if(textElement.type != TextElement::Type::TEXT)
             {
                 newTextElements.push_back(textElement);
@@ -225,10 +240,10 @@ namespace dchat
         }
         textElements = newTextElements;
         
+        // Split https
         newTextElements.clear();
-        for(size_t i = 0; i < textElements.size(); ++i)
+        for(const TextElement &textElement : textElements)
         {
-            TextElement textElement = textElements[i];
             if(textElement.type != TextElement::Type::TEXT)
             {
                 newTextElements.push_back(textElement);
@@ -333,10 +348,13 @@ namespace dchat
                 prevCodePoint = codePoint;
                 glyphPos.x += kerning;
                 
+                usize vertexStart = vertexOffset + i * 4;
+                
                 switch(codePoint)
                 {
                     case ' ':
                     {
+                        vertices[vertexStart].position = sf::Vector2f(glyphPos.x, glyphPos.y - vspace);
                         glyphPos.x += hspace;
                         if(glyphPos.x > maxWidth * 0.5f)
                         {
@@ -347,6 +365,7 @@ namespace dchat
                     }
                     case '\t':
                     {
+                        vertices[vertexStart].position = sf::Vector2f(glyphPos.x, glyphPos.y - vspace);
                         glyphPos.x += (hspace * TAB_WIDTH);
                         if(glyphPos.x > maxWidth * 0.5f)
                         {
@@ -357,12 +376,14 @@ namespace dchat
                     }
                     case '\n':
                     {
+                        vertices[vertexStart].position = sf::Vector2f(glyphPos.x, glyphPos.y - vspace);
                         glyphPos.x = 0.0f;
                         glyphPos.y += vspace + lineSpacing;
                         continue;
                     }
                     case '\v':
                     {
+                        vertices[vertexStart].position = sf::Vector2f(glyphPos.x, glyphPos.y - vspace);
                         glyphPos.y += (vspace * TAB_WIDTH) + lineSpacing;
                         continue;
                     }
@@ -408,10 +429,10 @@ namespace dchat
                 
                 sf::Color fontColor = (textElement.type == TextElement::Type::TEXT ? color : urlColor);
                 
-                vertices[vertexOffset + i * 4 + 0] = { vertexTopLeft, fontColor, textureTopLeft };
-                vertices[vertexOffset + i * 4 + 1] = { vertexTopRight, fontColor, textureTopRight };
-                vertices[vertexOffset + i * 4 + 2] = { vertexBottomRight, fontColor, textureBottomRight };
-                vertices[vertexOffset + i * 4 + 3] = { vertexBottomLeft, fontColor, textureBottomLeft };
+                vertices[vertexStart + 0] = { vertexTopLeft, fontColor, textureTopLeft };
+                vertices[vertexStart + 1] = { vertexTopRight, fontColor, textureTopRight };
+                vertices[vertexStart + 2] = { vertexBottomRight, fontColor, textureBottomRight };
+                vertices[vertexStart + 3] = { vertexBottomLeft, fontColor, textureBottomLeft };
                 
                 glyphPos.x += glyph.advance;
             }
@@ -433,14 +454,256 @@ namespace dchat
         totalHeight = glyphPos.y + vspace + lineSpacing;
     }
     
+    void Text::updateCaret()
+    {
+        assert(!dirty && !dirtyText);
+        switch(caretMoveDirection)
+        {
+            case CaretMoveDirection::UP:
+            {
+                caretIndex = getPreviousLineClosestPosition(caretIndex);
+                break;
+            }
+            case CaretMoveDirection::DOWN:
+            {
+                caretIndex = getNextLineClosestPosition(caretIndex);
+                break;
+            }
+            case CaretMoveDirection::HOME:
+            {
+                caretIndex = getStartOfLine(caretIndex);
+                break;
+            }
+            case CaretMoveDirection::END:
+            {
+                caretIndex = getEndOfLine(caretIndex);
+                break;
+            }
+            default:
+                // Ignore...
+                break;
+        }
+        
+        usize vertexIndex = caretIndex * 4;
+        const sf::Vertex &topLeftVertex = vertices[vertexIndex];
+        caretPosition = topLeftVertex.position;
+    }
+    
+    bool Text::isCaretAtEnd() const
+    {
+        assert(!dirty && !dirtyText);
+        return textElements[0].text.size == 0 || caretIndex == textElements[0].text.size;
+    }
+    
+    // TODO: This can be optimized by using step algorithm (jump to middle of vertices list and check if it's at next row, if not then divide by 2 again, and do this recursively)
+    int Text::getStartOfLine(int startIndex) const
+    {
+        assert(!dirty && !dirtyText);
+        int numVertices = vertices.getVertexCount();
+        if(numVertices < 4) return 0;
+        
+        usize vertexIndex = caretIndex * 4;
+        const sf::Vertex &startTopLeftVertex = vertices[vertexIndex];
+        int startRow = getRowByPosition(startTopLeftVertex.position);
+        for(int i = startIndex * 4; i >= 0; i -= 4)
+        {
+            const sf::Vertex &topLeftVertex = vertices[i];
+            int row = getRowByPosition(topLeftVertex.position);
+            if(row != startRow)
+            {
+                return std::max(0, i / 4 + 1);
+            }
+        }
+        return 0;
+    }
+    
+    // TODO: This can be optimized by using step algorithm (jump to middle of vertices list and check if it's at next row, if not then divide by 2 again, and do this recursively)
+    int Text::getEndOfLine(int startIndex) const
+    {
+        assert(!dirty && !dirtyText);
+        int numVertices = vertices.getVertexCount();
+        if(numVertices < 4) return 0;
+        
+        usize vertexIndex = caretIndex * 4;
+        const sf::Vertex &startTopLeftVertex = vertices[vertexIndex];
+        int startRow = getRowByPosition(startTopLeftVertex.position);
+        for(int i = startIndex * 4; i < numVertices; i += 4)
+        {
+            const sf::Vertex &topLeftVertex = vertices[i];
+            int row = getRowByPosition(topLeftVertex.position);
+            if(row != startRow)
+            {
+                return std::max(0, i / 4 - 1);
+            }
+        }
+        return numVertices / 4;
+    }
+    
+    // TODO: This can be optimized by using step algorithm (jump to middle of vertices list and check if it's at next row, if not then divide by 2 again, and do this recursively)
+    int Text::getPreviousLineClosestPosition(int startIndex) const
+    {
+        assert(!dirty && !dirtyText);
+        int numVertices = vertices.getVertexCount();
+        if(numVertices < 4) return 0;
+        
+        usize vertexIndex = caretIndex * 4;
+        const sf::Vertex &startTopLeftVertex = vertices[vertexIndex];
+        int startRow = getRowByPosition(startTopLeftVertex.position);
+        int closestIndex = -1;
+        float closestAbsoluteDiffX = 0.0f;
+        for(int i = startIndex * 4; i >= 0; i -= 4)
+        {
+            const sf::Vertex &topLeftVertex = vertices[i];
+            int row = getRowByPosition(topLeftVertex.position);
+            float absoluteDiffX = fabs(topLeftVertex.position.x - startTopLeftVertex.position.x);
+            int rowDiff = abs(row - startRow);
+            if(rowDiff > 1)
+                break;
+            
+            if(rowDiff == 1 && (closestIndex == -1 || absoluteDiffX < closestAbsoluteDiffX))
+            {
+                closestIndex = i;
+                closestAbsoluteDiffX = absoluteDiffX;
+            }
+        }
+        
+        if(closestIndex != -1)
+            return closestIndex / 4;
+        
+        return 0;
+    }
+    
+    // TODO: This can be optimized by using step algorithm (jump to middle of vertices list and check if it's at next row, if not then divide by 2 again, and do this recursively)
+    int Text::getNextLineClosestPosition(int startIndex) const
+    {
+        assert(!dirty && !dirtyText);
+        int numVertices = vertices.getVertexCount();
+        if(numVertices < 4) return 0;
+        
+        usize vertexIndex = caretIndex * 4;
+        const sf::Vertex &startTopLeftVertex = vertices[vertexIndex];
+        int startRow = getRowByPosition(startTopLeftVertex.position);
+        int closestIndex = -1;
+        float closestAbsoluteDiffX = 0.0f;
+        for(int i = startIndex * 4; i < numVertices; i += 4)
+        {
+            const sf::Vertex &topLeftVertex = vertices[i];
+            int row = getRowByPosition(topLeftVertex.position);
+            float absoluteDiffX = fabs(topLeftVertex.position.x - startTopLeftVertex.position.x);
+            int rowDiff = abs(row - startRow);
+            if(rowDiff > 1)
+                break;
+            
+            if(rowDiff == 1 && (closestIndex == -1 || absoluteDiffX < closestAbsoluteDiffX))
+            {
+                closestIndex = i;
+                closestAbsoluteDiffX = absoluteDiffX;
+            }
+        }
+        
+        if(closestIndex != -1)
+            return closestIndex / 4;
+        
+        return numVertices / 4;
+    }
+    
+    int Text::getRowByPosition(const sf::Vector2f &position) const
+    {
+        assert(!dirty && !dirtyText);
+        const float vspace = font->getLineSpacing(characterSize);
+        return static_cast<int>(1.0f + position.y / (vspace + lineSpacing));
+    }
+    
+    void Text::processEvent(const sf::Event &event)
+    {
+        if(!editable) return;
+        
+        if(event.type == sf::Event::KeyPressed)
+        {
+            if(event.key.code == sf::Keyboard::Left && caretIndex > 0)
+            {
+                --caretIndex;
+                dirtyCaret = true;
+            }
+            else if(event.key.code == sf::Keyboard::Right && !isCaretAtEnd())
+            {
+                ++caretIndex;
+                dirtyCaret = true;
+            }
+            else if(event.key.code == sf::Keyboard::BackSpace && caretIndex > 0)
+            {
+                auto strBefore = str.substring(0, caretIndex - 1);
+                auto strAfter = str.substring(caretIndex);
+                setString(strBefore + strAfter);
+                --caretIndex;
+                dirtyCaret = true;
+            }
+            else if(event.key.code == sf::Keyboard::Delete && !isCaretAtEnd())
+            {
+                auto strBefore = str.substring(0, caretIndex);
+                auto strAfter = str.substring(caretIndex + 1);
+                setString(strBefore + strAfter);
+            }
+            else if(event.key.code == sf::Keyboard::Up)
+            {
+                caretMoveDirection = CaretMoveDirection::UP;
+            }
+            else if(event.key.code == sf::Keyboard::Down)
+            {
+                caretMoveDirection = CaretMoveDirection::DOWN;
+            }
+            else if(event.key.code == sf::Keyboard::Home)
+            {
+                caretMoveDirection = CaretMoveDirection::HOME;
+            }
+            else if(event.key.code == sf::Keyboard::End)
+            {
+                caretMoveDirection = CaretMoveDirection::END;
+            }
+        }
+        else if(event.type == sf::Event::TextEntered)
+        {
+            if(event.text.unicode == 8 || event.text.unicode == 127) // backspace, del
+                return;
+            
+            if(isCaretAtEnd())
+                str += event.text.unicode;
+            else
+            {
+                auto strBefore = str.substring(0, caretIndex);
+                auto strAfter = str.substring(caretIndex);
+                str = strBefore + event.text.unicode + strAfter;
+            }
+            
+            ++caretIndex;
+            dirty = true;
+            dirtyText = true;
+            dirtyCaret = true;
+        }
+    }
+    
     void Text::draw(sf::RenderTarget &target, Cache &cache)
     {
+        if(dirtyText)
+        {
+            textElements.clear();
+            stringSplitElements(this->str, 0);
+            dirtyText = false;
+        }
+        
         if(dirty)
         {
             updateGeometry();
             dirty = false;
         }
         
+        if(dirtyCaret || caretMoveDirection != CaretMoveDirection::NONE)
+        {
+            updateCaret();
+            dirtyCaret = false;
+            caretMoveDirection = CaretMoveDirection::NONE;
+        }
+        
         float vspace = font->getLineSpacing(characterSize);
         
         sf::RenderStates states;
@@ -458,6 +721,7 @@ namespace dchat
         states.texture = &font->getTexture(characterSize);
         target.draw(vertices, states);
         
+        pos.y -= floor(vspace);
         for(TextElement &textElement : textElements)
         {
             if(textElement.type == TextElement::Type::EMOJI)
@@ -551,9 +815,8 @@ namespace dchat
                         }
                         case ContentByUrlResult::CachedType::WEB_PAGE_PREVIEW:
                         {
-                            const float previewWidth = floor(imageHeight * 1.77f);
+                            const float previewWidth = fmin(maxWidth, floor(imageHeight * 1.77f));
                             
-                            // No need to perform culling here, that is done in @Text draw function
                             contentByUrlResult.webPagePreview->title.setCharacterSize(characterSize);
                             contentByUrlResult.webPagePreview->title.setMaxWidth(previewWidth);
                             contentByUrlResult.webPagePreview->title.setPosition(pos);
@@ -573,5 +836,15 @@ namespace dchat
                 }
             }
         }
+        
+        if(!editable) return;
+        
+        //float rows = floor(totalHeight / (vspace + lineSpacing));
+        const float caretRow = getRowByPosition(caretPosition);
+        
+        sf::RectangleShape caretRect(sf::Vector2f(2.0f, floor(vspace)));
+        caretRect.setFillColor(sf::Color::White);
+        caretRect.setPosition(sf::Vector2f(floor(pos.x + caretPosition.x), floor(pos.y + caretRow * (vspace + lineSpacing))));
+        target.draw(caretRect);
     }
 }
diff --git a/src/UsersSidePanel.cpp b/src/UsersSidePanel.cpp
index f665d1f..9c04062 100644
--- a/src/UsersSidePanel.cpp
+++ b/src/UsersSidePanel.cpp
@@ -20,7 +20,7 @@ namespace dchat
     {
         float posY = ChannelTopPanel::getHeight();
         auto windowSize = window.getSize();
-        sf::RectangleShape rect(sf::Vector2f(getWidth(), windowSize.y));
+        sf::RectangleShape rect(sf::Vector2f(getWidth(), windowSize.y - ChannelTopPanel::getHeight()));
         rect.setFillColor(ColorScheme::getPanelColor());
         rect.setPosition(windowSize.x - getWidth(), posY);
         window.draw(rect);
@@ -45,6 +45,6 @@ namespace dchat
     
     float UsersSidePanel::getWidth()
     {
-        return WIDTH * Settings::getScaling();
+        return floor(WIDTH * Settings::getScaling());
     }
 }