feat: provide LSP API support

Signed-off-by: azerr <[email protected]>

docs/LSPApi.md

@@ -0,0 +1,93 @@
+# LSP server support
+
+The LSPCustomizedServerSupport API allows customizing the behavior of LSP features to customize:
+
+* [LSP completion support](#customize-lsp-completion-support)
+* [LSP diagnostic support](#customize-lsp-diagnostic-support)
+* [LSP formatting support](#customize-lsp-formatting-support)
+
+These custom supports are done:
+
+* by extending the default classes `LSPCustomized*Support` (e.g. creating a new class `MyLSPCustomizedFormattingSupport` that extends 
+[LSPCustomizedFormattingSupport](https://github.com/redhat-developer/lsp4ij/blob/main/src/main/java/com/redhat/devtools/lsp4ij/server/customization/LSPCustomizedFormattingSupport.java) to customize formatting support)
+and overriding some methods to customize the behavior.
+* registering your custom classes with `LanguageServerFactory#createServerSupport(@NotNull Project)`:
+
+```java
+package my.language.server;
+
+import com.intellij.openapi.project.Project;
+import com.redhat.devtools.lsp4ij.LanguageServerFactory;
+import com.redhat.devtools.lsp4ij.client.features.LSPCustomizedServerSupport;
+import org.jetbrains.annotations.NotNull;
+
+public class MyLanguageServerFactory implements LanguageServerFactory {
+
+    @Override
+    public @NotNull LSPCustomizedServerSupport createServerSupport(@NotNull Project project) {
+        return new LSPCustomizedServerSupport(project)
+                .withCompletionSupport(new MyLSPCustomizedCompletionSupport()) // customize LSP completion support
+                .withDiagnosticSupport(new MyLSPCustomizedDiagnosticSupport()) // customize LSP diagnostic support
+                .withFormattingSupport(new MyLSPCustomizedFormattingSupport()); // customize LSP formatting support         
+    }
+}
+```
+
+## Customize LSP completion support
+
+TODO
+
+## Customize LSP diagnostic support
+
+Here is an example of code that avoids creating an IntelliJ annotation when the LSP diagnostic code is equal to `ignore`:
+
+```java
+package my.language.server;
+
+import com.intellij.lang.annotation.HighlightSeverity;
+import com.redhat.devtools.lsp4ij.client.features.LSPCustomizedDiagnosticSupport;
+import org.eclipse.lsp4j.Diagnostic;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class MyLSPCustomizedDiagnosticSupport extends LSPCustomizedDiagnosticSupport {
+
+    @Override
+    public @Nullable HighlightSeverity getHighlightSeverity(@NotNull Diagnostic diagnostic) {
+        if (diagnostic.getCode() != null &&
+                diagnostic.getCode().isLeft() &&
+                "ignore".equals(diagnostic.getCode().getLeft())) {
+            // return a null HighlightSeverity when LSP diagnostic code is equals
+            // to 'ignore' to avoid creating an IntelliJ annotation
+            return null;
+        }
+        return super.getHighlightSeverity(diagnostic);
+    }
+
+}
+```
+
+## Customize LSP formatting support
+
+Here is an example of code that allows to execute the LSP formatter even if there is a specific formatter registered by an IntelliJ plugin
+
+TODO: revisit this API to manage range formatting too.
+
+```java
+package my.language.server;
+
+import com.intellij.psi.PsiFile;
+import com.redhat.devtools.lsp4ij.client.features.LSPCustomizedFormattingSupport;
+import com.redhat.devtools.lsp4ij.client.features.LSPCustomizedServerSupport;
+import org.jetbrains.annotations.NotNull;
+
+public class MyLSPCustomizedFormattingSupport extends LSPCustomizedFormattingSupport {
+
+    @Override
+    public boolean canSupportFormatting(@NotNull PsiFile file, boolean hasCustomFormatter) {
+        // By default, LSPCustomizedFormattingSupport return false if it has custom formatter with psi
+        // returns true even if there is custom formatter
+        return true;
+    }
+}
+```

src/main/java/com/redhat/devtools/lsp4ij/LanguageServerFactory.java

@@ -13,6 +13,7 @@
 import com.intellij.openapi.project.Project;
 import com.redhat.devtools.lsp4ij.client.LanguageClientImpl;
 import com.redhat.devtools.lsp4ij.server.StreamConnectionProvider;
+import com.redhat.devtools.lsp4ij.client.features.LSPServerFeatures;
 import org.eclipse.lsp4j.services.LanguageServer;
 import org.jetbrains.annotations.NotNull;
 
@@ -50,4 +51,7 @@ public interface LanguageServerFactory {
         return LanguageServer.class;
     }
 
+    @NotNull default LSPServerFeatures createServerSupport(@NotNull Project project) {
+        return new LSPServerFeatures(project);
+    }
 }

src/main/java/com/redhat/devtools/lsp4ij/LanguageServerWrapper.java

@@ -31,6 +31,7 @@
 import com.redhat.devtools.lsp4ij.lifecycle.LanguageServerLifecycleManager;
 import com.redhat.devtools.lsp4ij.lifecycle.NullLanguageServerLifecycleManager;
 import com.redhat.devtools.lsp4ij.server.*;
+import com.redhat.devtools.lsp4ij.client.features.LSPServerFeatures;
 import com.redhat.devtools.lsp4ij.server.definition.LanguageServerDefinition;
 import org.eclipse.lsp4j.*;
 import org.eclipse.lsp4j.jsonrpc.Launcher;
@@ -108,6 +109,8 @@ public class LanguageServerWrapper implements Disposable {
 
     private FileOperationsManager fileOperationsManager;
 
+    private LSPServerFeatures serverSupport;
+
     /* Backwards compatible constructor */
     public LanguageServerWrapper(@NotNull Project project, @NotNull LanguageServerDefinition serverDefinition) {
         this(project, serverDefinition, null);
@@ -1174,4 +1177,11 @@ public boolean isSignatureTriggerCharactersSupported(String charTyped) {
         }
         return triggerCharacters.contains(charTyped);
     }
+
+    public LSPServerFeatures getServerSupport() {
+        if (serverSupport == null) {
+            serverSupport = getServerDefinition().createServerSupport(getProject());
+        }
+        return serverSupport;
+    }
 }

src/main/java/com/redhat/devtools/lsp4ij/client/features/AbstractLSPFeature.java

@@ -0,0 +1,41 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Red Hat, Inc.
+ * Distributed under license by Red Hat, Inc. All rights reserved.
+ * This program is made available under the terms of the
+ * Eclipse Public License v2.0 which accompanies this distribution,
+ * and is available at https://www.eclipse.org/legal/epl-v20.html
+ *
+ * Contributors:
+ * Red Hat, Inc. - initial API and implementation
+ ******************************************************************************/
+package com.redhat.devtools.lsp4ij.client.features;
+
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Abstract class for any LSP customization feature support.
+ */
+@ApiStatus.Experimental
+public abstract class AbstractLSPFeature {
+
+    private LSPServerFeatures serverSupport;
+
+    /**
+     * Returns the LSP server support.
+     *
+     * @return the LSP server support.
+     */
+    public @NotNull LSPServerFeatures getServerSupport() {
+        return serverSupport;
+    }
+
+    /**
+     * Set the LSP server support.
+     *
+     * @param serverSupport the LSP server support.
+     */
+    public void setServerSupport(@NotNull LSPServerFeatures serverSupport) {
+        this.serverSupport = serverSupport;
+    }
+}

src/main/java/com/redhat/devtools/lsp4ij/client/features/LSPCompletionFeature.java

@@ -0,0 +1,21 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Red Hat, Inc.
+ * Distributed under license by Red Hat, Inc. All rights reserved.
+ * This program is made available under the terms of the
+ * Eclipse Public License v2.0 which accompanies this distribution,
+ * and is available at https://www.eclipse.org/legal/epl-v20.html
+ *
+ * Contributors:
+ * Red Hat, Inc. - initial API and implementation
+ ******************************************************************************/
+package com.redhat.devtools.lsp4ij.client.features;
+
+import org.jetbrains.annotations.ApiStatus;
+
+/**
+ * LSP customization completion support.
+ */
+@ApiStatus.Experimental
+public class LSPCompletionFeature extends AbstractLSPFeature {
+
+}