Add flat page host

Author: pcastornii

README.md

@@ -1,7 +1,7 @@
 # Techsenger TabShell
 
 Techsenger TabShell is a platform for building tab-based applications in JavaFX, where an application is structured
-as a tree of MVP components, each of which has its own lifecycle, history, etc. The platform provides abstract 
+as a tree of MVP components, each of which has its own lifecycle, history, etc. The platform provides abstract
 classes for creating the main types of components: tab, area, page, dialog, and popup, as well as containers for them.
 
 It also includes ready-to-use implementations of containers (including a docking layout) and dialogs (including a
@@ -36,6 +36,7 @@ TabShell is built on top of the [PatternFX](https://github.com/techsenger/patter
     * [TabHost](#layout-tab-host)
     * [DockHost](#layout-dock-host)
     * [PageHost](#layout-page-host)
+    * [TreePageHost](#layout-tree-page-host)
 * [Shared Components](#shared)
     * [FindBase](#shared-find-base)
     * [FindPanel](#shared-find-panel)
@@ -324,10 +325,12 @@ to which all other components are positioned. The main component can be an `Area
 ### PageHost <a name="layout-page-host"></a>
 
 `PageHost` is a simple component that displays `Page` components and performs their lazy initialization.
+It can be used to display navigable pages with a flat menu-like structure in diffent components - tabs, dialogs etc.
 
-It can be used to display navigable pages with a menu-like structure (similar to a website layout). Additionally,
-it is commonly used in dialogs with a navigation tree on the left and a content page on the right. A classic example
-is a settings dialog.
+### TreePageHost <a name="layout-tree-page-host"></a>
+
+`TreePageHost` is almost identical to `PageHost`, except for the menu structure: `PageHost` uses a flat menu
+(`ListView`), whereas `TreePageHost` uses a hierarchical menu (`TreeView`).
 
 ## Shared Components <a name="shared"></a>
 

tabshell-core/src/main/java/com/techsenger/tabshell/core/page/AbstractPagePresenter.java

@@ -27,9 +27,9 @@ public abstract class AbstractPagePresenter<V extends PageView, C extends PageCo
 
     private boolean selected;
 
-    private final PageItem<?> item;
+    private final PageItem item;
 
-    public AbstractPagePresenter(V view, PageItem<?> item) {
+    public AbstractPagePresenter(V view, PageItem item) {
         super(view);
         this.item = item;
     }
@@ -50,7 +50,7 @@ protected PageHistory getHistory() {
     }
 
     @Override
-    public PageItem<?> getItem() {
+    public PageItem getItem() {
         return item;
     }
 }

tabshell-core/src/main/java/com/techsenger/tabshell/core/page/DefaultPageDescriptor.java

@@ -16,73 +16,27 @@
 
 package com.techsenger.tabshell.core.page;
 
-import com.techsenger.annotations.Unmodifiable;
 import com.techsenger.tabshell.material.icon.Icon;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
 
 /**
  *
  * @author Pavel Castornii
  */
-public class DefaultPageDescriptor implements PageDescriptor {
+public class DefaultPageDescriptor extends DefaultPageItem implements PageDescriptor {
 
-    private final Icon<?> icon;
+    private final PageFactory<PageItem> factory;
 
-    private final String text;
-
-    private final PageFactory factory;
-
-    private PageDescriptor parent;
-
-    private final List<PageDescriptor> children = new ArrayList<>();
-
-    public DefaultPageDescriptor() {
-        this(null, null, null);
-    }
-
-    public DefaultPageDescriptor(String text, PageFactory factory) {
+    public DefaultPageDescriptor(String text, PageFactory<PageItem> factory) {
         this(null, text, factory);
     }
 
-    public DefaultPageDescriptor(Icon<?> icon, String text, PageFactory factory) {
+    public DefaultPageDescriptor(Icon<?> icon, String text, PageFactory<PageItem> factory) {
+        super(icon, text);
         this.factory = factory;
-        this.icon = icon;
-        this.text = text;
     }
 
     @Override
-    public PageFactory getFactory() {
+    public PageFactory<PageItem> getFactory() {
         return factory;
     }
-
-    @Override
-    public PageDescriptor getParent() {
-        return this.parent;
-    }
-
-    @Override
-    public @Unmodifiable List<PageDescriptor> getChildren() {
-        return Collections.unmodifiableList(this.children);
-    }
-
-    public void addChild(DefaultPageDescriptor item) {
-        this.children.add(item);
-        item.setParent(this);
-    }
-
-    @Override
-    public Icon<?> getIcon() {
-        return icon;
-    }
-
-    @Override
-    public String getText() {
-        return text;
-    }
-
-    void setParent(DefaultPageDescriptor parent) {
-        this.parent = parent;
-    }
 }

tabshell-core/src/main/java/com/techsenger/tabshell/core/page/DefaultPageItem.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2024-2026 Pavel Castornii.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.techsenger.tabshell.core.page;
+
+import com.techsenger.tabshell.material.icon.Icon;
+
+/**
+ *
+ * @author Pavel Castornii
+ */
+public class DefaultPageItem implements PageItem {
+
+    private final Icon<?> icon;
+
+    private final String text;
+
+    public DefaultPageItem(Icon<?> icon, String text) {
+        this.icon = icon;
+        this.text = text;
+    }
+
+    @Override
+    public Icon<?> getIcon() {
+        return icon;
+    }
+
+    @Override
+    public String getText() {
+        return text;
+    }
+
+}

tabshell-core/src/main/java/com/techsenger/tabshell/core/page/DefaultTreePageDescriptor.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2024-2026 Pavel Castornii.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.techsenger.tabshell.core.page;
+
+import com.techsenger.annotations.Unmodifiable;
+import com.techsenger.tabshell.material.icon.Icon;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ *
+ * @author Pavel Castornii
+ */
+public class DefaultTreePageDescriptor extends DefaultPageItem implements TreePageDescriptor {
+
+    private DefaultTreePageDescriptor parent;
+
+    private final List<DefaultTreePageDescriptor> children = new ArrayList<>();
+
+    private final PageFactory<TreePageItem> factory;
+
+    public DefaultTreePageDescriptor() {
+        this(null, null, null);
+    }
+
+    public DefaultTreePageDescriptor(String text, PageFactory<TreePageItem> factory) {
+        this(null, text, factory);
+    }
+
+    public DefaultTreePageDescriptor(Icon<?> icon, String text, PageFactory<TreePageItem> factory) {
+        super(icon, text);
+        this.factory = factory;
+    }
+
+    @Override
+    public PageFactory<TreePageItem> getFactory() {
+        return factory;
+    }
+
+    @Override
+    public TreePageDescriptor getParent() {
+        return this.parent;
+    }
+
+    @Override
+    public @Unmodifiable List<? extends TreePageDescriptor> getChildren() {
+        return Collections.unmodifiableList(this.children);
+    }
+
+    public void addChild(DefaultTreePageDescriptor item) {
+        this.children.add(item);
+        item.setParent(this);
+    }
+
+    private void setParent(DefaultTreePageDescriptor parent) {
+        this.parent = parent;
+    }
+}

tabshell-core/src/main/java/com/techsenger/tabshell/core/page/PageContainerFxView.java

@@ -16,15 +16,17 @@
 
 package com.techsenger.tabshell.core.page;
 
+import java.util.List;
+
 /**
  *
  * @author Pavel Castornii
  */
-public interface PageContainerFxView<P extends PageContainerPresenter<?, ?>> {
+public interface PageContainerFxView<P extends PageContainerPresenter<?, ?>> extends PageContainerView {
 
     interface Composer extends PageContainerComposer {
 
-        void setPages(PageDescriptor root, boolean showRoot);
+        void setPages(List<PageDescriptor> pages);
     }
 
     Composer getComposer();

tabshell-core/src/main/java/com/techsenger/tabshell/core/page/PageContainerPort.java

@@ -24,5 +24,7 @@ public interface PageContainerPort {
 
     PagePort getSelectedPage();
 
-    void selectPage(PageItem<?> item);
+    void selectPage(PageItem item);
+
+    void selectPage(int index);
 }

tabshell-core/src/main/java/com/techsenger/tabshell/core/page/PageDescriptor.java

@@ -20,7 +20,7 @@
  *
  * @author Pavel Castornii
  */
-public interface PageDescriptor extends PageItem<PageDescriptor> {
+public interface PageDescriptor extends PageItem {
 
-    PageFactory getFactory();
+    PageFactory<PageItem> getFactory();
 }

tabshell-core/src/main/java/com/techsenger/tabshell/core/page/PageFactory.java

@@ -20,13 +20,13 @@
  *
  * @author Pavel Castornii
  */
-public interface PageFactory {
+public interface PageFactory<T extends PageItem> {
 
     /**
      * Returns an initialized page.
      *
      * @param item
      * @return
      */
-    PageFxView<?> createAndInitialize(PageItem<?> item);
+    PageFxView<?> createAndInitialize(T item);
 }

tabshell-core/src/main/java/com/techsenger/tabshell/core/page/PageItem.java

@@ -16,24 +16,13 @@
 
 package com.techsenger.tabshell.core.page;
 
-import com.techsenger.annotations.Unmodifiable;
 import com.techsenger.tabshell.material.icon.Icon;
-import java.util.List;
 
 /**
  *
  * @author Pavel Castornii
  */
-public interface PageItem<T extends PageItem<T>> {
-
-    T getParent();
-
-    /**
-     * Returns an unmodifiable list of children.
-     *
-     * @return
-     */
-    @Unmodifiable List<T> getChildren();
+public interface PageItem {
 
     Icon<?> getIcon();