feat: add automatic screen scaling recommendation

debian/control

@@ -12,6 +12,9 @@ Build-Depends:  debhelper (>= 11),
  libglib2.0-dev,
  libdtk6gui-dev,
  libdtk6core-dev,
+ libx11-dev,
+ libxcb-randr0-dev,
+ libxcb1-dev,
 Standards-Version: 4.1.3
 Homepage: https://github.com/linuxdeepin
 

src/plugin-qt/xsettings/CMakeLists.txt

@@ -14,10 +14,9 @@ file(GLOB_RECURSE SRCS "*.h" "*.cpp")
 
 find_package(Qt${QT_VERSION_MAJOR} REQUIRED COMPONENTS Core DBus)
 find_package(Dtk${DTK_VERSION_MAJOR} REQUIRED COMPONENTS Gui Core)
-find_package(PkgConfig REQUIRED)
-
-pkg_check_modules(X11 REQUIRED IMPORTED_TARGET x11)
-pkg_check_modules(XCB REQUIRED IMPORTED_TARGET xcb)
+find_package(X11 REQUIRED)
+find_package(XCB REQUIRED)
+find_package(XCB REQUIRED COMPONENTS RANDR)
 
 add_library(${BIN_NAME} MODULE
     ${SRCS}
@@ -26,8 +25,9 @@ add_library(${BIN_NAME} MODULE
 target_link_libraries(${BIN_NAME}
     Qt${QT_VERSION_MAJOR}::Core
     Qt${QT_VERSION_MAJOR}::DBus
-    PkgConfig::X11
-    PkgConfig::XCB
+    X11::X11
+    XCB::XCB
+    XCB::RANDR
     Dtk${DTK_VERSION_MAJOR}::Core
 )
 macro(install_user_symlink filepath wantsdir)

src/plugin-qt/xsettings/impl/xsettingsmanager.cpp

@@ -8,12 +8,13 @@
 
 #include <QDBusPendingReply>
 #include <QDBusUnixFileDescriptor>
 #include <QDebug>
 #include <QDir>
 #include <QDirIterator>
+#include <QProcessEnvironment>
 #include <QStandardPaths>
 #include <QThreadPool>
 #include <QtMath>
 
 #include <fcntl.h>
 
@@ -29,7 +30,10 @@
     , m_xcbUtils(XcbUtils::getInstance())
 {
     connect(m_settingDconfig, &DTK_CORE_NAMESPACE::DConfig::valueChanged, this, &XSettingsManager::handleDConfigChangedCb);
+    setScreenScaleFactors(getScreenScaleFactors(), false);
+    adjustScaleFactor(getRecommendedScaleFactor());
     setSettings(getSettingsInSchema());
+
     updateDPI();
     updateXResources();
     QThreadPool::globalInstance()->start([this]() {
@@ -231,6 +235,123 @@
     setSettings(xsSetting);
 }
 
+double toListedScaleFactor(double s)
+{
+    const double min = 1.0;
+    const double max = 3.0;
+    const double step = 0.25;
+
+    if (s <= min) {
+        return min;
+    } else if (s >= max) {
+        return max;
+    }
+
+    for (double i = min; i <= max; i += step) {
+        if (i > s) {
+            double ii = i - step;
+            double d1 = s - ii;
+            double d2 = i - s;
+
+            if (d1 >= d2) {
+                return i;
+            } else {
+                return ii;
+            }
+        }
+    }
+    return max;
+}
+
+// calcRecommendedScaleFactor 计算推荐的缩放比
+double calcRecommendedScaleFactor(double widthPx, double heightPx, double widthMm, double heightMm)
+{
+    if (widthMm == 0.0 || heightMm == 0.0) {
+        return 1.0;
+    }
+    double lenPx = std::sqrt(std::pow(widthPx, 2) + std::pow(heightPx, 2));
+    double lenMm = std::sqrt(std::pow(widthMm, 2) + std::pow(heightMm, 2));
+
+    double lenPxStd = std::sqrt(std::pow(1920, 2) + std::pow(1080, 2)); // 标准分辨率对角线长度
+    double lenMmStd = std::sqrt(std::pow(477, 2) + std::pow(268, 2));   // 标准物理尺寸对角线长度
+
+    const double a = 0.00158;
+    double fix = (lenMm - lenMmStd) * (lenPx / lenPxStd) * a;
+    double scaleFactor = (lenPx / lenMm) / (lenPxStd / lenMmStd) + fix;
+
+    return toListedScaleFactor(scaleFactor);
+}
+
+double XSettingsManager::getRecommendedScaleFactor()
+{
+    QList<XcbUtils::MonitorSizeInfo> monitors = XcbUtils::getInstance().getMonitorSizeInfos();
+    if (monitors.isEmpty()) {
+        return 1.0;
+    }
+    // 允许用户通过 force-scale-factor.ini 强制设置全局缩放
+    double forceScaleFactor = getForceScaleFactor();
+    if (forceScaleFactor > 0.0) {
+        return forceScaleFactor;
+    }
+    double minScaleFactor = 3.0;
+    for (auto &&monitor : monitors) {
+        double scaleFactor = calcRecommendedScaleFactor(monitor.width, monitor.height, monitor.mmWidth, monitor.mmHeight);
+        if (minScaleFactor > scaleFactor) {
+            minScaleFactor = scaleFactor;
+        }
+    }
+    return minScaleFactor;
+}
+
+// GetForceScaleFactor 允许用户通过 force-scale-factor.ini 强制设置全局缩放
+double XSettingsManager::getForceScaleFactor()
+{
+    QString fileName = Utils::GetUserConfigDir() + "/deepin/force-scale-factor.ini";
+    KeyFile keyFile;
+    bool bSuccess = keyFile.loadFile(fileName);
+    if (bSuccess) {
+        bool ok = false;
+        double forceScaleFactor = keyFile.getStr("ForceScaleFactor", "scale").toDouble(&ok);
+        if (ok && forceScaleFactor >= 1.0 && forceScaleFactor <= 3.0) {
+            return forceScaleFactor;
+        }
+        qWarning() << "invalid forceScaleFactor:" << keyFile.getStr("ForceScaleFactor", "scale");
+    }
+    return -1.0;
+}
+
+void XSettingsManager::adjustScaleFactor(double recommendedScaleFactor)
+{
+    qDebug() << "recommended scale factor:" << recommendedScaleFactor;
+    double value = m_settingDconfig->value("scale-factor").toDouble();
+    if (value <= 0) {
+        ScaleFactors map;
+        map.insert("ALL", value);
+        setScreenScaleFactors(map, false);
+        // m_restartOSD = true;
+    }
+    QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
+    if (!env.value("STARTDDE_MIGRATE_SCALE_FACTOR").isEmpty()) {
+        double scaleFactor = getScaleFactor();
+        if (scaleFactor > 0.0) {
+            ScaleFactors map;
+            map.insert("", scaleFactor);
+            setScreenScaleFactorsForQt(map);
+        }
+        cleanUpDdeEnv();
+        return;
+    }
+    if (!QFile::exists("/etc/lightdm/deepin/qt-theme.ini")) {
+        // lightdm-deepin-greeter does not have the qt-theme.ini file yet.
+        double scaleFactor = getScaleFactor();
+        if (scaleFactor > 0.0) {
+            ScaleFactors map;
+            map.insert("", scaleFactor);
+            setScreenScaleFactorsForQt(map);
+        }
+    }
+}
+
 void XSettingsManager::updateDPI()
 {
     double scale = 1;

src/plugin-qt/xsettings/impl/xsettingsmanager.h

@@ -42,6 +42,9 @@ protected Q_SLOTS:
     void handleDConfigChangedCb(const QString &key);
 
 private:
+    double getRecommendedScaleFactor();
+    double getForceScaleFactor();
+    void adjustScaleFactor(double recommendedScaleFactor);
     void updateDPI();
     void updateXResources();
     void updateFirefoxDPI();

src/plugin-qt/xsettings/modules/api/xcbutils.cpp

@@ -3,9 +3,10 @@
 // SPDX-License-Identifier: LGPL-3.0-or-later
 #include "xcbutils.h"
 
 #include <X11/X.h>
 #include <X11/Xatom.h>
 #include <X11/Xlib.h>
+#include <xcb/randr.h>
 #include <xcb/xcb.h>
 
 #include <stdio.h>
@@ -181,6 +182,72 @@
     return "";
 }
 
+QList<XcbUtils::MonitorSizeInfo> XcbUtils::getMonitorSizeInfos()
+{
+    // 获取XCB版本信息
+    const xcb_setup_t *setup = xcb_get_setup(connection);
+    int majorVersion = setup->protocol_major_version;
+    int minorVersion = setup->protocol_minor_version;
+    qInfo() << QString("randr version %1.%2").arg(majorVersion).arg(minorVersion);
+    if (majorVersion < 1 || (majorVersion == 1 && minorVersion < 2)) {
+        return {};
+    }
+    xcb_screen_iterator_t screen_iter = xcb_setup_roots_iterator(setup);
+    xcb_window_t root = screen_iter.data->root;
+    xcb_randr_get_screen_resources_cookie_t cookie = xcb_randr_get_screen_resources(connection, root);
+    xcb_generic_error_t *error = nullptr;
+    xcb_randr_get_screen_resources_reply_t *resources = xcb_randr_get_screen_resources_reply(connection, cookie, &error);
+    if (error) {
+        qWarning() << "Error getting screen resources: " << error->error_code;
+        free(error);
+        return {};
+    }
+
+    xcb_randr_output_t *outputs = xcb_randr_get_screen_resources_outputs(resources);
+    int output_count = xcb_randr_get_screen_resources_outputs_length(resources);
+    QList<MonitorSizeInfo> monitors;
+    for (int i = 0; i < output_count; i++) {
+        xcb_randr_output_t output = outputs[i];
+        xcb_randr_get_output_info_cookie_t info_cookie = xcb_randr_get_output_info(connection, output, resources->config_timestamp);
+
+        xcb_randr_get_output_info_reply_t *output_info = xcb_randr_get_output_info_reply(connection, info_cookie, nullptr);
+
+        if (!output_info)
+            continue;
+
+        // 检查输出是否连接
+        if (output_info->connection != XCB_RANDR_CONNECTION_CONNECTED) {
+            free(output_info);
+            continue;
+        }
+
+        if (output_info->crtc == XCB_NONE) {
+            free(output_info);
+            continue;
+        }
+        xcb_randr_get_crtc_info_cookie_t crtc_cookie = xcb_randr_get_crtc_info(connection, output_info->crtc, resources->config_timestamp);
+
+        xcb_randr_get_crtc_info_reply_t *crtc_info = xcb_randr_get_crtc_info_reply(connection, crtc_cookie, nullptr);
+
+        if (crtc_info) {
+            MonitorSizeInfo monitor;
+            monitor.width = crtc_info->width;
+            monitor.height = crtc_info->height;
+            monitor.mmWidth = output_info->mm_width;
+            monitor.mmHeight = output_info->mm_height;
+
+            monitors.push_back(monitor);
+
+            free(crtc_info);
+        }
+
+        free(output_info);
+    }
+
+    free(resources);
+    return monitors;
+}
+
 // 获取 _XSETTINGS_SETTINGS 属性
 QByteArray XcbUtils::getXcbAtomProperty(xcb_atom_t atom)
 {

src/plugin-qt/xsettings/modules/api/xcbutils.h

@@ -14,6 +14,14 @@ class XcbUtils : public QObject
 {
     Q_OBJECT
 public:
+    struct MonitorSizeInfo
+    {
+        uint16_t width;
+        uint16_t height;
+        uint32_t mmWidth;
+        uint32_t mmHeight;
+    };
+
     static XcbUtils &getInstance();
     xcb_window_t createWindows();
     xcb_atom_t getAtom(const char *name, bool exist = false);
@@ -28,6 +36,7 @@ class XcbUtils : public QObject
     QByteArray getXcbAtomProperty(xcb_atom_t atom);
     QByteArray xcbPropertyReplyDataToArray(xcb_get_property_reply_t *reply);
     QString getXcbAtomName(xcb_atom_t atom);
+    QList<MonitorSizeInfo> getMonitorSizeInfos();
 
 private:
     XcbUtils(QObject *parent = nullptr);