feat: block launch if Java is incompatible

Keep track of compatible Java versions from meta. Launch-step
VerifyJavaInstall will check if current instance's Java version is
compatible.
Also add override option both globally and per-instance in-case the user
doesn't care about the requirement.

launcher/Application.cpp

@@ -682,6 +682,7 @@ Application::Application(int &argc, char **argv) : QApplication(argc, argv)
         m_settings->registerSetting("JavaVendor", "");
         m_settings->registerSetting("LastHostname", "");
         m_settings->registerSetting("JvmArgs", "");
+        m_settings->registerSetting("IgnoreJavaCompatibility", false);
 
         // Native library workarounds
         m_settings->registerSetting("UseNativeOpenAL", false);

launcher/minecraft/LaunchProfile.cpp

@@ -126,6 +126,11 @@ void LaunchProfile::applyMods(const QList<LibraryPtr>& mods)
     }
 }
 
+void LaunchProfile::applyCompatibleJavaMajors(QList<int>& javaMajor)
+{
+    m_compatibleJavaMajors.append(javaMajor);
+}
+
 void LaunchProfile::applyLibrary(LibraryPtr library)
 {
     if(!library->isActive())
@@ -275,6 +280,11 @@ const QList<LibraryPtr> & LaunchProfile::getMavenFiles() const
     return m_mavenFiles;
 }
 
+const QList<int> & LaunchProfile::getCompatibleJavaMajors() const
+{
+    return m_compatibleJavaMajors;
+}
+
 void LaunchProfile::getLibraryFiles(
     const QString& architecture,
     QStringList& jars,

launcher/minecraft/LaunchProfile.h

@@ -21,6 +21,7 @@ public: /* application of profile variables from patches */
     void applyMods(const QList<LibraryPtr> &jarMods);
     void applyLibrary(LibraryPtr library);
     void applyMavenFile(LibraryPtr library);
+    void applyCompatibleJavaMajors(QList<int>& javaMajor);
     void applyMainJar(LibraryPtr jar);
     void applyProblemSeverity(ProblemSeverity severity);
     /// clear the profile
@@ -39,6 +40,7 @@ public: /* getters for profile variables */
     const QList<LibraryPtr> & getLibraries() const;
     const QList<LibraryPtr> & getNativeLibraries() const;
     const QList<LibraryPtr> & getMavenFiles() const;
+    const QList<int> & getCompatibleJavaMajors() const;
     const LibraryPtr getMainJar() const;
     void getLibraryFiles(
         const QString & architecture,
@@ -99,6 +101,9 @@ private:
     /// the list of mods
     QList<LibraryPtr> m_mods;
 
+    /// compatible java major versions
+    QList<int> m_compatibleJavaMajors;
+
     ProblemSeverity m_problemSeverity = ProblemSeverity::None;
 
 };

launcher/minecraft/MinecraftInstance.cpp

@@ -88,6 +88,7 @@ MinecraftInstance::MinecraftInstance(SettingsObjectPtr globalSettings, SettingsO
 
     m_settings->registerOverride(globalSettings->getSetting("JavaPath"), javaOrLocation);
     m_settings->registerOverride(globalSettings->getSetting("JvmArgs"), javaOrArgs);
+    m_settings->registerOverride(globalSettings->getSetting("IgnoreJavaCompatibility"), javaOrLocation);
 
     // special!
     m_settings->registerPassthrough(globalSettings->getSetting("JavaTimestamp"), javaOrLocation);

launcher/minecraft/MojangVersionFormat.cpp

@@ -183,6 +183,15 @@ void MojangVersionFormat::readVersionProperties(const QJsonObject &in, VersionFi
             );
         }
     }
+
+    if (in.contains("compatibleJavaMajors"))
+    {
+        for (auto compatible : requireArray(in.value("compatibleJavaMajors")))
+        {
+            out->compatibleJavaMajors.append(requireInteger(compatible));
+        }
+    }
+
     if(in.contains("downloads"))
     {
         auto downloadsObj = requireObject(in, "downloads");

launcher/minecraft/VersionFile.cpp

@@ -36,6 +36,7 @@ void VersionFile::applyTo(LaunchProfile *profile)
     profile->applyJarMods(jarMods);
     profile->applyMods(mods);
     profile->applyTraits(traits);
+    profile->applyCompatibleJavaMajors(compatibleJavaMajors);
 
     for (auto library : libraries)
     {

launcher/minecraft/VersionFile.h

@@ -57,6 +57,9 @@ public: /* data */
     /// Mojang: Minecraft launch arguments (may contain placeholders for variable substitution)
     QString minecraftArguments;
 
+    /// Mojang: list of compatible java majors
+    QList<int> compatibleJavaMajors;
+
     /// Mojang: type of the Minecraft version
     QString type;
 

launcher/minecraft/launch/VerifyJavaInstall.cpp

@@ -1,50 +1,40 @@
 #include "VerifyJavaInstall.h"
 
-#include <launch/LaunchTask.h>
+#include "java/JavaVersion.h"
-#include <minecraft/MinecraftInstance.h>
+#include "minecraft/PackProfile.h"
-#include <minecraft/PackProfile.h>
+#include "minecraft/MinecraftInstance.h"
-#include <minecraft/VersionFilterData.h>
-
-#ifdef major
-    #undef major
-#endif
-#ifdef minor
-    #undef minor
-#endif
 
 void VerifyJavaInstall::executeTask() {
-    auto m_inst = std::dynamic_pointer_cast<MinecraftInstance>(m_parent->instance());
+    auto instance = std::dynamic_pointer_cast<MinecraftInstance>(m_parent->instance());
+    auto packProfile = instance->getPackProfile();
+    auto settings = instance->settings();
+    auto storedVersion = settings->get("JavaVersion").toString();
+    auto ignoreCompatibility = settings->get("IgnoreJavaCompatibility").toBool();
 
-    auto javaVersion = m_inst->getJavaVersion();
+    auto compatibleMajors = packProfile->getProfile()->getCompatibleJavaMajors();
-    auto minecraftComponent = m_inst->getPackProfile()->getComponent("net.minecraft");
 
-    // Java 17 requirement
+    JavaVersion javaVersion(storedVersion);
-    if (minecraftComponent->getReleaseDateTime() >= g_VersionFilterData.java17BeginsDate) {
-        if (javaVersion.major() < 17) {
-            emit logLine("Minecraft 1.18 Pre Release 2 and above require the use of Java 17",
-                         MessageLevel::Fatal);
-            emitFailed(tr("Minecraft 1.18 Pre Release 2 and above require the use of Java 17"));
-            return;
-        }
-    }
-    // Java 16 requirement
-    else if (minecraftComponent->getReleaseDateTime() >= g_VersionFilterData.java16BeginsDate) {
-        if (javaVersion.major() < 16) {
-            emit logLine("Minecraft 21w19a and above require the use of Java 16",
-                         MessageLevel::Fatal);
-            emitFailed(tr("Minecraft 21w19a and above require the use of Java 16"));
-            return;
-        }
-    }
-    // Java 8 requirement
-    else if (minecraftComponent->getReleaseDateTime() >= g_VersionFilterData.java8BeginsDate) {
-        if (javaVersion.major() < 8) {
-            emit logLine("Minecraft 17w13a and above require the use of Java 8",
-                         MessageLevel::Fatal);
-            emitFailed(tr("Minecraft 17w13a and above require the use of Java 8"));
-            return;
-        }
-    }
 
+    if (compatibleMajors.isEmpty() || compatibleMajors.contains(javaVersion.major()))
+    {
         emitSucceeded();
+        return;
+    }
+
+
+    if (ignoreCompatibility)
+    {
+        emit logLine(tr("Java major version is incompatible. Things might break."), MessageLevel::Warning);
+        emitSucceeded();
+        return;
+    }
+
+    emit logLine(tr("Instance not compatible with Java major version %1.\n"
+                    "Switch the Java version of this instance to one of the following:").arg(javaVersion.major()),
+                 MessageLevel::Error);
+    for (auto major: compatibleMajors)
+    {
+        emit logLine(tr("Java %1").arg(major), MessageLevel::Error);
+    }
+    emitFailed(QString("Incompatible Java major version"));
 }

launcher/minecraft/launch/VerifyJavaInstall.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <launch/LaunchStep.h>
+#include <launch/LaunchTask.h>
 
 class VerifyJavaInstall : public LaunchStep {
     Q_OBJECT

launcher/ui/pages/global/JavaPage.cpp

@@ -95,6 +95,7 @@ void JavaPage::applySettings()
     // Java Settings
     s->set("JavaPath", ui->javaPathTextBox->text());
     s->set("JvmArgs", ui->jvmArgsTextBox->text());
+    s->set("IgnoreJavaCompatibility", ui->skipCompatibilityCheckbox->isChecked());
     JavaCommon::checkJVMArgs(s->get("JvmArgs").toString(), this->parentWidget());
 }
 void JavaPage::loadSettings()
@@ -118,6 +119,7 @@ void JavaPage::loadSettings()
     // Java Settings
     ui->javaPathTextBox->setText(s->get("JavaPath").toString());
     ui->jvmArgsTextBox->setText(s->get("JvmArgs").toString());
+    ui->skipCompatibilityCheckbox->setChecked(s->get("IgnoreJavaCompatibility").toBool());
 }
 
 void JavaPage::on_javaDetectBtn_clicked()

launcher/ui/pages/global/JavaPage.ui

@@ -222,6 +222,22 @@
             </property>
            </widget>
           </item>
+          <item row="4" column="1">
+           <widget class="QCheckBox" name="skipCompatibilityCheckbox">
+            <property name="sizePolicy">
+             <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
+             </sizepolicy>
+            </property>
+            <property name="toolTip">
+             <string>If enabled, the launcher will not check if an instance is compatible with the selected Java version.</string>
+            </property>
+            <property name="text">
+             <string>Skip Java compatibility checks</string>
+            </property>
+           </widget>
+          </item>
          </layout>
         </widget>
        </item>

launcher/ui/pages/instance/InstanceSettingsPage.cpp

@@ -165,10 +165,12 @@ void InstanceSettingsPage::applySettings()
     if (javaInstall)
     {
         m_settings->set("JavaPath", ui->javaPathTextBox->text());
+        m_settings->set("IgnoreJavaCompatibility", ui->skipCompatibilityCheckbox->isChecked());
     }
     else
     {
         m_settings->reset("JavaPath");
+        m_settings->reset("IgnoreJavaCompatibility");
     }
 
     // Java arguments
@@ -286,6 +288,7 @@ void InstanceSettingsPage::loadSettings()
 
     ui->javaSettingsGroupBox->setChecked(overrideLocation);
     ui->javaPathTextBox->setText(m_settings->get("JavaPath").toString());
+    ui->skipCompatibilityCheckbox->setChecked(m_settings->get("IgnoreJavaCompatibility").toBool());
 
     ui->javaArgumentsGroupBox->setChecked(overrideArgs);
     ui->jvmArgsTextBox->setPlainText(m_settings->get("JvmArgs").toString());

launcher/ui/pages/instance/InstanceSettingsPage.ui

@@ -85,6 +85,16 @@
             </property>
            </widget>
           </item>
+          <item row="2" column="0">
+           <widget class="QCheckBox" name="skipCompatibilityCheckbox">
+            <property name="toolTip">
+             <string>If enabled, the launcher will not check if an instance is compatible with the selected Java version.</string>
+            </property>
+            <property name="text">
+             <string>Skip Java compatibility checks</string>
+            </property>
+           </widget>
+          </item>
          </layout>
         </widget>
        </item>