#228 Draft a naive "Wetherell and Shannon" implementation. WIP.

Signed-off-by: cneben <benoit@destrat.io>

samples/layouts/CMakeLists.txt

@@ -23,11 +23,14 @@ endif()
 
 set(source_files
     layouts.cpp
+    qanOrgTreeLayout.cpp
 )
 
-set (header_files)
+set (header_files
+     qanOrgTreeLayout.h
+)
 
-add_executable(sample_layouts ${source_files} layouts.qrc)
+add_executable(sample_layouts ${source_files} ${header_files} layouts.qrc)
 target_include_directories(sample_layouts PUBLIC QuickQanava Qt${QT_VERSION_MAJOR}::QuickControls2)
 target_link_libraries(sample_layouts
     QuickQanava

samples/layouts/qanOrgTreeLayout.cpp

@@ -0,0 +1,73 @@
+/*
+ Copyright (c) 2008-2024, Benoit AUTHEMAN All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+    * Neither the name of the author or Destrat.io nor the
+      names of its contributors may be used to endorse or promote products
+      derived from this software without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY
+ DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+//-----------------------------------------------------------------------------
+// This file is a part of the QuickQanava software library.
+//
+// \file	qanOrgTreeLayout.h
+// \author	benoit@destrat.io
+// \date	2024 08 13
+//-----------------------------------------------------------------------------
+
+// Std headers
+#include <memory>
+
+// Qt headers
+#include <QQmlProperty>
+#include <QVariant>
+#include <QQmlEngine>
+#include <QQmlComponent>
+
+// QuickQanava headers
+#include "./qanOrgTreeLayout.h"
+
+namespace qan { // ::qan
+
+/* OrgTreeLayout Object Management *///----------------------------------------
+OrgTreeLayout::OrgTreeLayout(QObject* parent) noexcept :
+    QObject{parent}
+{
+}
+
+OrgTreeLayout::~OrgTreeLayout()
+{
+}
+
+void    OrgTreeLayout::layout(qan::Node& root) noexcept
+{
+    // Pre-condition: root must be a tree subgraph, this is not enforced in this methodod.
+
+    // Algorithm:
+    // 1. Use BFS to generate an array of nodes "level by level".
+    // 2. Layout the tree bottom up
+    // 3. Shift the tree to align root to it's original position.
+
+    // 1. BFS
+
+}
+//-----------------------------------------------------------------------------
+
+} // ::qan

samples/layouts/qanOrgTreeLayout.h

@@ -0,0 +1,86 @@
+/*
+ Copyright (c) 2008-2024, Benoit AUTHEMAN All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+    * Neither the name of the author or Destrat.io nor the
+      names of its contributors may be used to endorse or promote products
+      derived from this software without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY
+ DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+//-----------------------------------------------------------------------------
+// This file is a part of the QuickQanava software library.
+//
+// \file	qanOrgTreeLayout.h
+// \author	benoit@destrat.io
+// \date	2024 08 13
+//-----------------------------------------------------------------------------
+
+#pragma once
+
+// Qt headers
+#include <QString>
+#include <QQuickItem>
+#include <QQmlParserStatus>
+#include <QSharedPointer>
+#include <QAbstractListModel>
+
+// QuickQanava headers
+#include "../../src/qanGraph.h"
+
+
+namespace qan { // ::qan
+
+/*! \brief
+ * \nosubgrouping
+ */
+class OrgTreeLayout : public QObject
+{
+    Q_OBJECT
+    /*! \name OrgTreeLayout Object Management *///-----------------------------
+    //@{
+public:
+    explicit OrgTreeLayout(QObject* parent = nullptr) noexcept;
+    virtual ~OrgTreeLayout() override;
+    OrgTreeLayout(const OrgTreeLayout&) = delete;
+    OrgTreeLayout& operator=(const OrgTreeLayout&) = delete;
+    OrgTreeLayout(OrgTreeLayout&&) = delete;
+    OrgTreeLayout& operator=(OrgTreeLayout&&) = delete;
+
+public:
+    /*! \brief Apply an "organisational chart tree layout algorithm" to subgraph \c root.
+     *
+     * OrgChart layout _will preserve_ node orders.
+     *
+     * While the current implementation is not "space optimal" it run in O(n), n beeing the
+     * number of nodes in root "tree subgraph".
+     *
+     * \note \c root must be a tree subgraph, this method will not enforce this condition,
+     * running this algorithm on a non tree subgraph might lead to inifinite recursions or
+     * invalid layouts.
+     */
+    Q_INVOKABLE virtual void    layout(qan::Node& root) noexcept;
+    //@}
+    //-------------------------------------------------------------------------
+};
+
+} // ::qan
+
+QML_DECLARE_TYPE(qan::OrgTreeLayout)
+