Automatically retrieve and update liquid app icons

.github/workflows/ci.yml

@@ -40,14 +40,14 @@ jobs:
     - name: Resolve dependencies (Ubuntu, Qt 5)
       run: |
         sudo apt-get update
-        sudo apt-get install -y qtbase5-dev qtwebengine5-dev qt5-qmake libx11-dev
+        sudo apt-get install -y qtbase5-dev qtwebengine5-dev libqt5svg5-dev qt5-qmake libx11-dev
         echo "QMAKE=qmake" >> "$GITHUB_ENV"
       if: runner.os == 'Linux' && matrix.qt == 5
 
     - name: Resolve dependencies (Ubuntu, Qt 6)
       run: |
         sudo apt-get update
-        sudo apt-get install -y qt6-base-dev qt6-webengine-dev qmake6 libgl-dev libx11-dev
+        sudo apt-get install -y qt6-base-dev qt6-webengine-dev qt6-svg-dev qmake6 libgl-dev libx11-dev
         echo "QMAKE=qmake6" >> "$GITHUB_ENV"
       if: runner.os == 'Linux' && matrix.qt == 6
 

README.md

@@ -76,17 +76,19 @@ What gets stored (if allowed): cookies.
 
 #### Dependencies
 
-Liquid is built with Qt 6 (Qt 5.15 is still supported) and Qt WebEngine.
+Liquid is built with Qt 6 (Qt 5.15 is still supported), Qt WebEngine, and Qt SVG.
 
 On Debian/Ubuntu:
 
 ```console
-sudo apt install qt6-base-dev qt6-webengine-dev qmake6 libx11-dev build-essential
+sudo apt install qt6-base-dev qt6-webengine-dev qt6-svg-dev qmake6 libx11-dev build-essential
 ```
 
+For Qt 5.15, the packages are `qtbase5-dev qtwebengine5-dev libqt5svg5-dev qt5-qmake` instead.
+
 Optionally, also install `qt6-base-private-dev` (requires Qt 6.5 or newer): it lets Liquid bring windows of already running Liquid apps to front on Wayland, instead of the desktop environment merely showing a notification.
 
-On macOS and Windows, install Qt 6 with the Qt WebEngine, Qt WebChannel, and Qt Positioning modules using the [Qt Online Installer](https://www.qt.io/download-qt-installer).
+On macOS and Windows, install Qt 6 with the Qt WebEngine, Qt WebChannel, and Qt Positioning modules (Qt SVG comes with Qt itself) using the [Qt Online Installer](https://www.qt.io/download-qt-installer).
 
 #### Build
 

inc/liquid.hpp

@@ -18,6 +18,8 @@ class Liquid
     static QDir getDataDir(void);
     static QString getLiquidAppFilePath(const QString liquidAppName);
     static QString getDefaultUserAgentString(void);
+    static QString getDesktopFilePath(const QString liquidAppName);
+    static QString getDesktopFileIconValue(const QString liquidAppName);
     static QStringList getLiquidAppsList(void);
     static void raiseWindow(QWidget* window, const QString activationToken = QString());
     static void requestActivationToken(QWidget* window, const std::function<void(const QString&)> callback);
@@ -27,4 +29,5 @@ class Liquid
     static void removeDesktopFile(const QString liquidAppName);
     static void runLiquidApp(const QString liquidAppName, const QString activationToken = QString());
     static void sleep(const int ms);
+    static void updateDesktopFileIcon(const QString liquidAppName);
 };

inc/liquidappconfigwindow.hpp

@@ -13,6 +13,8 @@
 #include <QtGui>
 #include <QtWidgets>
 
+#include "liquidappicon.hpp"
+
 class LiquidAppConfigDialog : public QDialog
 {
 public:
@@ -49,6 +51,9 @@ public slots:
     QLineEdit* nameInput;
     QLineEdit* addressInput;
     QCheckBox* createIconCheckBox;
+    QToolButton* iconButton;
+    LiquidAppIcon chosenIcon;
+    bool iconWasEdited = false;
     QCheckBox* planningToRunCheckBox = Q_NULLPTR;
 
     // General tab

inc/liquidappicon.hpp

@@ -0,0 +1,92 @@
+#pragma once
+
+#include <QByteArray>
+#include <QIcon>
+#include <QImage>
+#include <QList>
+#include <QObject>
+#include <QSettings>
+#include <QUrl>
+
+#include "lqd.h"
+
+class QNetworkAccessManager;
+class QNetworkReply;
+class QWebEnginePage;
+
+// A Liquid app's icon: either an SVG image (kept as-is, so it stays sharp at any size), or a raster one (kept as PNG);
+// stored inside .liquid files, with a copy next to them for .desktop files to point at
+class LiquidAppIcon
+{
+public:
+    LiquidAppIcon(void) {}
+
+    // Accepts SVG and any raster format Qt can read (picking the largest image for files containing several, e.g. .ico);
+    // SVG images that could make whatever displays them reach out for something (e.g. external images) get rasterized
+    static LiquidAppIcon fromData(const QByteArray& data);
+    static LiquidAppIcon fromImage(const QImage& image);
+    static LiquidAppIcon fromIcon(const QIcon& icon); // Takes the largest image the icon contains
+
+    // The Liquid app's own icon (null if it doesn't have one yet)
+    static LiquidAppIcon load(QSettings* liquidAppConfig);
+
+    // The Liquid app's own icon, or Liquid's icon if it doesn't have one yet
+    static QIcon loadIcon(QSettings* liquidAppConfig);
+
+    // Makes this the Liquid app's icon
+    void save(QSettings* liquidAppConfig, const QString& liquidAppName) const;
+
+    // Takes the icon away from the Liquid app (it'll get fetched from the website again)
+    static void remove(QSettings* liquidAppConfig, const QString& liquidAppName);
+
+    // Puts the icon file in place (for .desktop files) if it's missing, e.g. for icons from older versions of Liquid
+    static void ensureIconFile(QSettings* liquidAppConfig, const QString& liquidAppName);
+
+    // Where the copy of the icon for .desktop files lives (an empty string if there's none)
+    static QString getIconFilePath(const QString& liquidAppName);
+    static void removeIconFile(const QString& liquidAppName);
+
+    bool isNull(void) const;
+    bool isSvg(void) const;
+
+    // How good of an icon this is (vector images beat raster ones of any size)
+    int score(void) const;
+
+    QImage toImage(const int size = LQD_ICON_MAX_SIZE) const;
+    QIcon toIcon(void) const;
+
+private:
+    QByteArray svg;
+    QImage image;
+};
+
+// Finds the best icon a website has to offer (looking at the page that's currently shown), downloads all candidates
+// and picks the best one
+class LiquidAppIconFetcher : public QObject
+{
+    Q_OBJECT
+
+public:
+    LiquidAppIconFetcher(QWebEnginePage* page, QObject* parent = Q_NULLPTR);
+
+    void start(void);
+
+signals:
+    // The icon is null if no usable one has been found
+    void finished(const LiquidAppIcon& icon);
+
+private:
+    void onPageInspected(const QString& json);
+    void download(const QUrl& url, const bool isMaskable);
+    void onDownloaded(QNetworkReply* reply, const bool isMaskable);
+    void onManifestDownloaded(QNetworkReply* reply);
+    void finishIfDone(void);
+
+    QWebEnginePage* page;
+    QNetworkAccessManager* networkAccessManager;
+    QList<QUrl> requestedUrls;
+    int pendingRequestCount = 0;
+    LiquidAppIcon bestIcon;
+    qreal bestScore = 0;
+    bool isDone = false;
+};

inc/liquidappwindow.hpp

@@ -14,6 +14,8 @@
 
 #include "liquidappwebpage.hpp"
 
+class LiquidAppIcon;
+class LiquidAppIconFetcher;
 class LiquidAppWebPage;
 class SnapshotFlashOverlay;
 class QPainter;
@@ -75,11 +77,20 @@ public slots:
     QVariant runJavaScriptSync(const QString& js, const int timeoutMs = 5000);
     void waitForNextFrame(void);
     bool waitForDocumentToFinishLoading(void);
+    void applyIcon(void);
+    void maybeFetchIcon(void);
+    void useFetchedIcon(const LiquidAppIcon& icon);
+    bool isShowingOwnWebsite(void);
 
     QString liquidAppName;
 
     QString liquidAppWindowTitle;
-    QIcon iconToSave;
+
+    // The icon provided by the page that's currently shown (used only until the Liquid app has an icon of its own)
+    QIcon pageIcon;
+    // Fetching the website's icon happens once per run, and only if the Liquid app doesn't have one yet
+    LiquidAppIconFetcher* iconFetcher = Q_NULLPTR;
+    bool iconFetchAttempted = false;
 
     LiquidAppWebPage* liquidAppWebPage = Q_NULLPTR;
     QWebEngineProfile* liquidAppWebProfile = Q_NULLPTR;

inc/lqd.h

@@ -4,6 +4,7 @@
 #define LQD_PROG_TITLE         "Liquid"
 #define LQD_APPS_DIR_NAME      "apps"
 #define LQD_APP_FILE_EXTENSION "liquid"
+#define LQD_ICONS_DIR_NAME     "icons" // Copies of Liquid apps' icons, for .desktop files to point at
 #define LQD_DEFAULT_BG_COLOR   Qt::white
 #define LQD_DEFAULT_PROXY_HOST "0.0.0.0"
 #define LQD_DEFAULT_PROXY_PORT 8080
@@ -36,12 +37,18 @@
 #define LQD_INSTANCE_MSG_PREVIEW_CSS      "preview-css"        // Liquid apps only, followed by a space and base64-encoded CSS
 #define LQD_INSTANCE_MSG_PREVIEW_FRAME    "preview-frame"      // Liquid apps only, followed by a space and "on" or "off"
 #define LQD_INSTANCE_MSG_PREVIEW_SCROLL   "preview-scrollbars" // Liquid apps only, followed by a space and "on" or "off"
+#define LQD_INSTANCE_MSG_ICON_CHANGED    "icon-changed"    // Main window only, followed by a space and Liquid app's name
 #define LQD_INSTANCE_MSG_STARTED         "started"         // Main window only, followed by a space and Liquid app's name
 #define LQD_ACTIVATION_TOKEN_TIMEOUT     500               // Milliseconds to wait for the compositor to issue an activation token
 #define LQD_PREVIEW_CONNECT_TIMEOUT      100               // Milliseconds to wait for connecting to a Liquid app for previewing settings
 #define LQD_RECREATED_WINDOW_RAISE_DELAY 100               // Milliseconds to wait before bringing a re-created native window to front
 #define LQD_SCROLLBARS_RELAYOUT_DELAY    100               // Milliseconds to keep the document unscrollable for, to make it redo its scrollbars
 #define LQD_CSS_PREVIEW_DELAY            150               // Milliseconds to wait after the last keystroke before previewing CSS
+#define LQD_ICON_DOWNLOAD_TIMEOUT        10000             // Milliseconds to wait for an icon (or web app manifest) to download
+#define LQD_ICON_MAX_CANDIDATES          16                // How many icons a website gets to offer at most
+#define LQD_ICON_MAX_FILE_SIZE           (4 * 1024 * 1024) // Bytes
+#define LQD_ICON_MAX_SVG_SIZE            (512 * 1024)      // Bytes, larger SVG icons get rasterized
+#define LQD_ICON_MAX_SIZE                256               // Pixels, larger icons get scaled down before they get stored
 #define LQD_INSTANCE_STOP_TIMEOUT        5000              // Milliseconds to wait for a Liquid app to quit
 
 /* Names of scripts Liquid injects into web pages */

inc/mainwindow.hpp

@@ -15,6 +15,7 @@ class MainWindow : public QScrollArea
     ~MainWindow();
 
     // Starts keeping track of the Liquid app by the given name (called when Liquid apps report being started)
+    void updateLiquidAppIcon(const QString& liquidAppName);
     void watchLiquidApp(const QString& liquidAppName);
 
 protected:

liquid.pro

@@ -4,7 +4,7 @@ VERSION_PATCH = 11
 
 VERSION      = $${VERSION_MAJOR}.$${VERSION_MINOR}.$${VERSION_PATCH}
 
-QT          += core gui network widgets webenginecore webenginewidgets
+QT          += core gui network svg widgets webenginecore webenginewidgets
 CONFIG      += c++17
 TEMPLATE     = app
 
@@ -25,6 +25,7 @@ INCLUDEPATH += $${INC_DIR}
 HEADERS     += inc/lqd.h \
                inc/liquid.hpp \
                inc/liquidappfile.hpp \
+               inc/liquidappicon.hpp \
                inc/liquidappcookiejar.hpp \
                inc/liquidappconfigwindow.hpp \
                inc/liquidappwebpage.hpp \
@@ -35,6 +36,7 @@ HEADERS     += inc/lqd.h \
 
 SOURCES     += src/liquid.cpp \
                src/liquidappfile.cpp \
+               src/liquidappicon.cpp \
                src/liquidappcookiejar.cpp \
                src/liquidappconfigwindow.cpp \
                src/liquidappwebpage.cpp \

src/liquid.cpp

@@ -1,5 +1,6 @@
 #include "lqd.h"
 #include "liquid.hpp"
+#include "liquidappicon.hpp"
 #if defined(Q_OS_UNIX) && !defined(Q_OS_MACOS)
 #include "liquidx11.h"
 #endif
@@ -73,7 +74,7 @@ void Liquid::createDesktopFile(const QString liquidAppName, const QString liquid
     context += "[Desktop Entry]\n";
     context += "Type=Application\n";
     context += "Name=" + liquidAppName + "\n";
-    context += "Icon=internet-web-browser\n";
+    context += "Icon=" + getDesktopFileIconValue(liquidAppName) + "\n";
     context += "Exec=liquid " + liquidAppName + "\n";
     context += "Comment=" + liquidAppStartingUrl + "\n";
     context += "Categories=Network;WebBrowser;\n";
@@ -103,6 +104,49 @@ void Liquid::createDesktopFile(const QString liquidAppName, const QString liquid
 #endif
 }
 
+QString Liquid::getDesktopFilePath(const QString liquidAppName)
+{
+    // QString desktopPath = QStandardPaths::writableLocation(QStandardPaths::DesktopLocation);
+    return QDir::homePath() + QDir::separator() + "Desktop" + QDir::separator() + liquidAppName + ".desktop";
+}
+
+QString Liquid::getDesktopFileIconValue(const QString liquidAppName)
+{
+    const QString iconFilePath = LiquidAppIcon::getIconFilePath(liquidAppName);
+
+    return (iconFilePath.isEmpty()) ? "internet-web-browser" : iconFilePath;
+}
+
+void Liquid::updateDesktopFileIcon(const QString liquidAppName)
+{
+#if defined(Q_OS_LINUX)
+    // Only the icon gets changed, the rest of the file may have been edited by the user
+    QFile file(getDesktopFilePath(liquidAppName));
+    if (!file.open(QIODevice::ReadOnly)) {
+        return;
+    }
+    QStringList lines = QString::fromUtf8(file.readAll()).split('\n');
+    file.close();
+
+    bool changed = false;
+    for (QString& line : lines) {
+        if (line.startsWith("Icon=")) {
+            const QString newLine = "Icon=" + getDesktopFileIconValue(liquidAppName);
+            changed = changed || line != newLine;
+            line = newLine;
+        }
+    }
+
+    // Writing in place keeps the file's permissions (it has to remain executable)
+    if (changed && file.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
+        file.write(lines.join('\n').toUtf8());
+        file.close();
+    }
+#else
+    Q_UNUSED(liquidAppName);
+#endif
+}
+
 bool Liquid::detectDarkMode(void)
 {
     // Detecting it may involve spawning a process, do it only once per program run