Add image preview and url/image open in browser

1 files changed, 168 insertions, 0 deletions

diff --git a/src/ImagePreview.cpp b/src/ImagePreview.cpp
new file mode 100644
index 0000000..0b36dbd
--- /dev/null
+++ b/src/ImagePreview.cpp
@@ -0,0 +1,168 @@
+#include "../include/ImagePreview.hpp"
+#include "../include/Settings.hpp"
+#include "../include/StringUtils.hpp"
+#include "../include/Gif.hpp"
+#include <SFML/Graphics/RectangleShape.hpp>
+#include <cassert>
+
+namespace dchat
+{
+    static const float PADDING_VERTICAL = 40.0f;
+    static const float PADDING_HORIZONTAL = 40.0f;
+    
+    static ImagePreview *instance = nullptr;
+    static std::string imagePreviewUrl;
+    
+    ImagePreview* ImagePreview::getInstance()
+    {
+        if(!instance)
+            instance = new ImagePreview();
+        return instance;
+    }
+    
+    void ImagePreview::preview(sf::Texture *texture, const std::string &url)
+    {
+        if(texture == getInstance()->texture) return;
+        getInstance()->texture = texture;
+        getInstance()->contentType = texture ? ContentType::TEXTURE : ContentType::NONE;
+        imagePreviewUrl = url;
+        if(texture)
+            getInstance()->sprite.setTexture(*texture, true);
+        else
+            getInstance()->sprite = sf::Sprite();
+    }
+    
+    void ImagePreview::preview(Gif *gif, const std::string &url)
+    {
+        if(gif == getInstance()->gif) return;
+        getInstance()->gif = gif;
+        getInstance()->contentType = gif ? ContentType::GIF : ContentType::NONE;
+        imagePreviewUrl = url;
+        getInstance()->sprite = sf::Sprite();
+    }
+    
+    void* ImagePreview::getPreviewContentPtr()
+    {
+        return getInstance()->texture;
+    }
+    
+    sf::Int32 ImagePreview::getTimeSinceLastSeenMs()
+    {
+        return getInstance()->lastSeenTimer.getElapsedTime().asMilliseconds();
+    }
+    
+    void ImagePreview::processEvent(const sf::Event &event)
+    {
+        if(getInstance()->contentType == ContentType::NONE) return;
+        
+        if(event.mouseButton.button == sf::Mouse::Button::Left)
+        {
+            sf::Vector2f imagePos;
+            switch(getInstance()->contentType)
+            {
+                case ContentType::TEXTURE:
+                    imagePos = getInstance()->sprite.getPosition();
+                    break;
+                case ContentType::GIF:
+                    imagePos = getInstance()->gif->getPosition();
+                    break;
+            }
+            getInstance()->sprite.getPosition();
+            const auto &imageSize = getInstance()->size;
+            bool mouseInside = false;
+            if(event.mouseButton.x >= imagePos.x && event.mouseButton.x <= imagePos.x + imageSize.x && 
+                event.mouseButton.y >= imagePos.y && event.mouseButton.y <= imagePos.y + imageSize.y)
+            {
+                mouseInside = true;
+            }
+            
+            if(event.type == sf::Event::MouseButtonPressed && mouseInside && !imagePreviewUrl.empty())
+            {
+                // TODO: Implement for other platforms than linux
+                std::string escapedUrl = stringReplaceChar(imagePreviewUrl, "'", "");
+                escapedUrl = stringReplaceChar(escapedUrl, "\\", "");
+                std::string cmd = "xdg-open '";
+                cmd += escapedUrl;
+                cmd += "'";
+                printf("Clicked on web page preview, opening web page by running command: %s\n", cmd.c_str());
+                system(cmd.c_str());
+            }
+            else if(event.type == sf::Event::MouseButtonReleased && !mouseInside)
+            {
+                ImagePreview::preview((sf::Texture*)nullptr);
+            }
+        }
+        else if(event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Escape)
+        {
+            ImagePreview::preview((sf::Texture*)nullptr);
+        }
+    }
+    
+    void ImagePreview::draw(sf::RenderWindow &window)
+    {
+        if(getInstance()->contentType == ContentType::NONE) return;
+        
+        auto windowSize = window.getSize();
+        sf::RectangleShape background(sf::Vector2f(windowSize.x, windowSize.y));
+        background.setFillColor(sf::Color(0, 0, 0, 200));
+        
+        auto imageSize = getInstance()->calculateImageSize(windowSize);
+        getInstance()->size = imageSize;
+        
+        window.draw(background);
+        switch(getInstance()->contentType)
+        {
+            case ContentType::TEXTURE:
+            {
+                auto textureSize = getInstance()->sprite.getTexture()->getSize();
+                getInstance()->sprite.setPosition(windowSize.x / 2 - imageSize.x / 2, windowSize.y / 2 - imageSize.y / 2);
+                getInstance()->sprite.setScale((double)imageSize.x / (double)textureSize.x, (double)imageSize.y / (double)textureSize.y);
+                window.draw(getInstance()->sprite);
+                break;
+            }
+            case ContentType::GIF:
+            {
+                auto textureSize = getInstance()->gif->getSize();
+                getInstance()->gif->setPosition(sf::Vector2f(windowSize.x / 2 - imageSize.x / 2, windowSize.y / 2 - imageSize.y / 2));
+                getInstance()->gif->setScale(sf::Vector2f((double)imageSize.x / (double)textureSize.x, (double)imageSize.y / (double)textureSize.y));
+                getInstance()->gif->draw(window);
+                break;
+            }
+        }
+        getInstance()->lastSeenTimer.restart();
+    }
+    
+    sf::Vector2u ImagePreview::calculateImageSize(sf::Vector2u windowSize) const
+    {
+        assert(contentType != ContentType::NONE);
+        sf::Vector2u imageMaxSize(windowSize.x - PADDING_HORIZONTAL * Settings::getScaling() * 2.0f, windowSize.y - PADDING_VERTICAL * Settings::getScaling() * 2.0f);
+        sf::Vector2u textureSize;
+        switch(contentType)
+        {
+            case ContentType::TEXTURE:
+                textureSize = texture->getSize();
+                break;
+            case ContentType::GIF:
+                textureSize = gif->getSize();
+                break;
+        }
+        auto imageSize = textureSize;
+        double textureWidthHeightRatio = (double)imageSize.x / (double)imageSize.y;
+        double textureHeightWidthRatio = (double)imageSize.y / (double)imageSize.x;
+        
+        int overflowVertical = (int)imageSize.y - (int)imageMaxSize.y;
+        if(overflowVertical > 0)
+        {
+            imageSize.y = imageMaxSize.y;
+            imageSize.x -= (overflowVertical * textureWidthHeightRatio);
+        }
+        
+        int overflowHorizontal = (int)imageSize.x - (int)imageMaxSize.x;
+        if(overflowHorizontal > 0)
+        {
+            imageSize.x = imageMaxSize.x;
+            imageSize.y -= (overflowHorizontal * textureHeightWidthRatio);
+        }
+        return imageSize;
+    }
+}