Implement retained target sessions, runtime sizing and Component navigation

designer-contracts/src/main/java/de/neitzel/fxdesigner/config/DesignerConfiguration.java

@@ -13,8 +13,26 @@ public record DesignerConfiguration(String schemaVersion, Map<String, Context> c
       String module,
       String provider,
       String defaultExample,
-      List<String> examples) {
+      List<String> examples,
+      int requestTimeoutSeconds,
+      int readinessTimeoutSeconds) {
+    public Preview(
+        String sourceSet,
+        String module,
+        String provider,
+        String defaultExample,
+        List<String> examples) {
+      this(sourceSet, module, provider, defaultExample, examples, 30, 20);
+    }
+
     public Preview {
+      if (requestTimeoutSeconds == 0) requestTimeoutSeconds = 30;
+      if (readinessTimeoutSeconds == 0) readinessTimeoutSeconds = 20;
+      if (requestTimeoutSeconds < 1
+          || requestTimeoutSeconds > 300
+          || readinessTimeoutSeconds < 1
+          || readinessTimeoutSeconds > requestTimeoutSeconds)
+        throw new IllegalArgumentException("Invalid preview deadlines");
       examples = List.copyOf(examples);
     }
   }

designer-contracts/src/main/java/de/neitzel/fxdesigner/protocol/LayoutMetrics.java

@@ -0,0 +1,65 @@
+package de.neitzel.fxdesigner.protocol;
+
+import java.util.Map;
+
+/** Logical target pixels; finite Double.MAX_VALUE represents an unbounded maximum. */
+public record LayoutMetrics(
+    String occurrence,
+    double minWidth,
+    double prefWidth,
+    double maxWidth,
+    double minHeight,
+    double prefHeight,
+    double maxHeight,
+    double baseline,
+    String bias) {
+  public LayoutMetrics {
+    if (occurrence == null || occurrence.isBlank() || occurrence.length() > 4096)
+      throw new IllegalArgumentException("Invalid occurrence");
+    for (double value :
+        new double[] {minWidth, prefWidth, maxWidth, minHeight, prefHeight, maxHeight, baseline})
+      if (!Double.isFinite(value) || value < 0)
+        throw new IllegalArgumentException("Invalid target measurement");
+    if (!java.util.Set.of("NONE", "HORIZONTAL", "VERTICAL").contains(bias))
+      throw new IllegalArgumentException("Invalid content bias");
+  }
+
+  public Map<String, String> encode() {
+    return Map.of(
+        "occurrence",
+        occurrence,
+        "minWidth",
+        "" + minWidth,
+        "prefWidth",
+        "" + prefWidth,
+        "maxWidth",
+        "" + maxWidth,
+        "minHeight",
+        "" + minHeight,
+        "prefHeight",
+        "" + prefHeight,
+        "maxHeight",
+        "" + maxHeight,
+        "baseline",
+        "" + baseline,
+        "bias",
+        bias);
+  }
+
+  public static LayoutMetrics decode(Map<String, String> m) {
+    return new LayoutMetrics(
+        m.get("occurrence"),
+        number(m, "minWidth"),
+        number(m, "prefWidth"),
+        number(m, "maxWidth"),
+        number(m, "minHeight"),
+        number(m, "prefHeight"),
+        number(m, "maxHeight"),
+        number(m, "baseline"),
+        m.get("bias"));
+  }
+
+  private static double number(Map<String, String> m, String key) {
+    return Double.parseDouble(m.get(key));
+  }
+}

designer-contracts/src/main/java/de/neitzel/fxdesigner/protocol/ProtocolSession.java

@@ -72,11 +72,23 @@ public final class ProtocolSession implements AutoCloseable {
     if (hello.preview().major() == 1
         && supported.contains("render-rgba-v1")
         && hello.capabilities().contains("render-rgba-v1")) usable.add(Operation.RENDER);
+    if (hello.preview().major() == 1
+        && supported.contains("layout-v1")
+        && hello.capabilities().contains("layout-v1")) {
+      usable.add(Operation.MEASURE);
+      usable.add(Operation.OCCURRENCES);
+    }
+    if (hello.preview().major() == 1
+        && supported.contains("interactive-v1")
+        && hello.capabilities().contains("interactive-v1")) usable.add(Operation.INTERACTIVE);
     var requiredByEither = new HashSet<>(required);
     requiredByEither.addAll(hello.required());
     if ((requiredByEither.contains("discover-v1") && !usable.contains(Operation.DISCOVER))
         || (requiredByEither.contains("render-rgba-v1") && !usable.contains(Operation.RENDER)))
       throw new IllegalArgumentException("Required capability version incompatible");
+    if ((requiredByEither.contains("layout-v1") && !usable.contains(Operation.MEASURE))
+        || (requiredByEither.contains("interactive-v1") && !usable.contains(Operation.INTERACTIVE)))
+      throw new IllegalArgumentException("Required capability version incompatible");
     operations = Set.copyOf(usable);
     state = State.READY;
     return operations;

designer-contracts/src/main/java/de/neitzel/fxdesigner/protocol/WireProtocol.java

@@ -73,7 +73,10 @@ public final class WireProtocol {
 
   public enum Operation {
     DISCOVER,
-    RENDER
+    RENDER,
+    MEASURE,
+    OCCURRENCES,
+    INTERACTIVE
   }
 
   public record Identity(
@@ -111,14 +114,14 @@ public final class WireProtocol {
       Objects.requireNonNull(operation);
       Objects.requireNonNull(identity);
       Objects.requireNonNull(payload);
-      boolean render = operation == Operation.RENDER;
+      boolean render = operation != Operation.DISCOVER;
       if (render
           && (identity.width() == 0 || identity.height() == 0 || identity.revisions().isEmpty()))
         throw new IllegalArgumentException("Rendering needs dimensions and document revisions");
       if (!render
           && (identity.width() != 0 || identity.height() != 0 || !identity.revisions().isEmpty()))
         throw new IllegalArgumentException("Discovery does not carry render identity");
-      boolean image = render && kind == Kind.RESULT;
+      boolean image = operation == Operation.RENDER && kind == Kind.RESULT;
       if (image
           ? payload.length != (long) identity.width() * identity.height() * 4
           : payload.length > MAX_METADATA)