Implement basic ui

Changes:

 - Clean up code to use Qt coding style
 - Add comments to some methods
 - Add debugtools to have debug_msg() and debug_err() macros
 - New Serializer class header to save / load data
 - MetadataDialog: check validity of metadata
 - MainWindow: initial code for `tool' buttons to edit the structogram
 - MainWindow: open / save dialog

15 files changed, 323 insertions, 53 deletions

diff --git a/OrbitingYeti.pro b/OrbitingYeti.pro
index 2353696..7351c0c 100644
--- a/OrbitingYeti.pro
+++ b/OrbitingYeti.pro
@@ -33,7 +33,8 @@ SOURCES += \
     src/diagram/statement.cpp \
     src/diagram/structogram.cpp \
     src/ui/metadatadialog.cpp \
-    src/ui/painter.cpp
+    src/ui/painter.cpp \
+    src/io/serializer.cpp
 
 HEADERS += \
     include/ui/mainwindow.h \
@@ -43,7 +44,9 @@ HEADERS += \
     include/diagram/iteratorstatement.h \
     include/diagram/branchstatement.h \
     include/ui/metadatadialog.h \
-    include/ui/painter.h
+    include/ui/painter.h \
+    include/debugtools.h \
+    include/io/serializer.h
 
 FORMS += \
     forms/mainwindow.ui \
diff --git a/README.md b/README.md
index 911a52f..bd18385 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,4 @@
 # OrbitingYeti: a tool to write Nassi-Schneidermann diagrams
 
-## TO DO list / Roadmap
-
-- [ ] Structogram data structure
-- [ ] GUI with Qt5
-- [ ] PDF Generator
+## Coding style
+[https://wiki.qt.io/Qt_Coding_Style]
diff --git a/forms/mainwindow.ui b/forms/mainwindow.ui
index 86d6381..23125a1 100644
--- a/forms/mainwindow.ui
+++ b/forms/mainwindow.ui
@@ -165,7 +165,7 @@
     </widget>
     <addaction name="actionNew"/>
     <addaction name="actionSave"/>
-    <addaction name="actionSave_As"/>
+    <addaction name="actionSaveAs"/>
     <addaction name="actionOpen"/>
     <addaction name="actionClose"/>
     <addaction name="menuExport"/>
@@ -255,11 +255,20 @@
    </property>
   </action>
   <action name="actionPDF">
+   <property name="enabled">
+    <bool>true</bool>
+   </property>
    <property name="text">
     <string>PDF</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+E</string>
+   </property>
   </action>
   <action name="actionLaTeX_TikZ">
+   <property name="enabled">
+    <bool>true</bool>
+   </property>
    <property name="text">
     <string>LaTeX TikZ</string>
    </property>
@@ -280,7 +289,7 @@
     <string>Ctrl+V</string>
    </property>
   </action>
-  <action name="actionSave_As">
+  <action name="actionSaveAs">
    <property name="text">
     <string>Save As</string>
    </property>
@@ -327,5 +336,70 @@
   </action>
  </widget>
  <resources/>
- <connections/>
+ <connections>
+  <connection>
+   <sender>actionNew</sender>
+   <signal>triggered()</signal>
+   <receiver>newButton</receiver>
+   <slot>click()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>-1</x>
+     <y>-1</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>23</x>
+     <y>53</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>actionSave</sender>
+   <signal>triggered()</signal>
+   <receiver>saveButton</receiver>
+   <slot>click()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>-1</x>
+     <y>-1</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>99</x>
+     <y>53</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>actionOpen</sender>
+   <signal>triggered()</signal>
+   <receiver>openButton</receiver>
+   <slot>click()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>-1</x>
+     <y>-1</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>61</x>
+     <y>53</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>actionQuit</sender>
+   <signal>triggered()</signal>
+   <receiver>MainWindow</receiver>
+   <slot>close()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>-1</x>
+     <y>-1</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>411</x>
+     <y>300</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
 </ui>
diff --git a/forms/metadatadialog.ui b/forms/metadatadialog.ui
index 070242e..62fca5c 100644
--- a/forms/metadatadialog.ui
+++ b/forms/metadatadialog.ui
@@ -11,19 +11,9 @@
    </rect>
   </property>
   <property name="windowTitle">
-   <string>Set metadata</string>
+   <string>Metadata</string>
   </property>
   <layout class="QFormLayout" name="formLayout">
-   <item row="5" column="1">
-    <widget class="QDialogButtonBox" name="buttonBox">
-     <property name="orientation">
-      <enum>Qt::Horizontal</enum>
-     </property>
-     <property name="standardButtons">
-      <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
-     </property>
-    </widget>
-   </item>
    <item row="1" column="1">
     <widget class="QLabel" name="titleLabel">
      <property name="text">
@@ -44,6 +34,19 @@
    <item row="4" column="1">
     <widget class="QLineEdit" name="authorEdit"/>
    </item>
+   <item row="5" column="1">
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="enabled">
+      <bool>true</bool>
+     </property>
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
+     </property>
+    </widget>
+   </item>
   </layout>
  </widget>
  <resources/>
diff --git a/include/debugtools.h b/include/debugtools.h
new file mode 100644
index 0000000..cd6940b
--- /dev/null
+++ b/include/debugtools.h
@@ -0,0 +1,27 @@
+#ifndef DEBUGTOOLS_H
+#define DEBUGTOOLS_H
+
+#ifdef QT_NO_DEBUG
+
+void debug_msg(...) {}
+void debug_err(...) {}
+
+#else
+#include <iostream>
+
+#define debug_msg(msg) \
+do { \
+    std::cout << "DEBUG [" \
+              << __FILE__ << " @ " << __LINE__ \
+              << "]: " << msg << std::endl; \
+} while (0)
+
+#define debug_err(msg) \
+do { \
+    std::cerr << "ERROR [" \
+              << __FILE__ << " @ " << __LINE__ \
+              << "]: " << msg << std::endl; \
+} while (0)
+
+#endif // QT_NO_DEBUG
+#endif // DEBUGTOOLS_H
diff --git a/include/diagram/branchstatement.h b/include/diagram/branchstatement.h
index 6c5e416..3d8c385 100644
--- a/include/diagram/branchstatement.h
+++ b/include/diagram/branchstatement.h
@@ -8,13 +8,15 @@
 
 namespace samb {
 
+/* Implementation for Statement::DECISION, Statement::SWITCH
+ */
 class BranchStatement : public Statement
 {
 public:
     BranchStatement(Type t, const QString &condition, pointer next);
 
     /* accessors */
-    const std::map<QString, pointer>& branches() const { return _branches; }
+    std::map<QString, pointer>& branches() { return _branches; }
     std::size_t branches_count() const { return _branchesCount; }
 
     inline const QString& condition() const { return text(); }
diff --git a/include/diagram/iteratorstatement.h b/include/diagram/iteratorstatement.h
index a8f6d59..e7fbba0 100644
--- a/include/diagram/iteratorstatement.h
+++ b/include/diagram/iteratorstatement.h
@@ -8,13 +8,15 @@
 
 namespace samb {
 
+/* Implementation for Statement::WHILE Statement::UNTIL
+ */
 class IteratorStatement : public Statement
 {
 public:
     IteratorStatement(Type t, const QString &condition, pointer next);
 
     /* accessors */
-    const Scope& inner() const { return _inner; }
+    Scope& inner() { return _inner; }
 
     inline const QString& condition() const { return text(); }
     inline void condition(const QString &condition) { return text(condition); }
diff --git a/include/diagram/structogram.h b/include/diagram/structogram.h
index 6b2e0db..cd501aa 100644
--- a/include/diagram/structogram.h
+++ b/include/diagram/structogram.h
@@ -7,15 +7,19 @@
 
 namespace samb {
 
+/* A structogram is a specific type of scope, that is the root scope.
+ * As a result it contains some metadata informations about the author,
+ * date of creation ecc.
+ */
 class Structogram : public Scope
 {
 public:
     Structogram(const QString &title, const QString &author);
-    ~Structogram();
+    virtual ~Structogram();
 
     /* accessors */
-    void title(const QString &title) { text(title); }
-    const QString& title() const { return text(); }
+    inline void title(const QString &title) { text(title); }
+    inline const QString& title() const { return text(); }
 
     void author(const QString &author) { _author = author; }
     const QString& author() const { return _author; }
diff --git a/include/io/serializer.h b/include/io/serializer.h
new file mode 100644
index 0000000..901d913
--- /dev/null
+++ b/include/io/serializer.h
@@ -0,0 +1,18 @@
+#ifndef SERIALIZER_H
+#define SERIALIZER_H
+
+#include "diagram/structogram.h"
+
+#include <QFileInfo>
+
+class Serializer
+{
+public:
+    explicit Serializer();
+    virtual ~Serializer();
+
+    bool write(const samb::Structogram &structogram, QFileInfo into);
+    bool load(samb::Structogram &structogram, QFileInfo from);
+};
+
+#endif // SERIALIZER_H
diff --git a/include/ui/mainwindow.h b/include/ui/mainwindow.h
index 0beb4a2..3061440 100644
--- a/include/ui/mainwindow.h
+++ b/include/ui/mainwindow.h
@@ -19,13 +19,19 @@ public:
 
 private slots:
     void on_newButton_clicked();
+    void on_openButton_clicked();
+    void on_saveButton_clicked();
+
+    void on_refreshButton_clicked();
     void on_metadataButton_clicked();
+    void on_newStatementButton_clicked();
 
 private:
     Ui::MainWindow *_ui;
     samb::Structogram *_structogram;
 
-    void initData();
+    bool askSaveDialog();
+    void toolButtonsEnabled(bool state);
 };
 
 #endif // MAINWINDOW_H
diff --git a/include/ui/metadatadialog.h b/include/ui/metadatadialog.h
index 0ed2f17..81af9da 100644
--- a/include/ui/metadatadialog.h
+++ b/include/ui/metadatadialog.h
@@ -2,6 +2,7 @@
 #define NEWDIALOG_H
 
 #include <QDialog>
+#include <QAbstractButton>
 
 namespace Ui {
 class MetadataDialog;
@@ -15,10 +16,15 @@ public:
     explicit MetadataDialog(QWidget *parent = 0);
     ~MetadataDialog();
 
+    bool isValid() const;
     void setMetadata(const QString& title, const QString& author);
     QString title() const;
     QString author() const;
 
+private slots:
+    void on_titleEdit_textChanged();
+    void on_authorEdit_textChanged();
+
 private:
     Ui::MetadataDialog *_ui;
 };
diff --git a/src/diagram/scope.cpp b/src/diagram/scope.cpp
index 5f6b4df..b0f56cf 100644
--- a/src/diagram/scope.cpp
+++ b/src/diagram/scope.cpp
@@ -17,8 +17,7 @@ Scope::iterator::~iterator()
 
 Scope::iterator& Scope::iterator::operator++()
 {
-    if (_current->next() == nullptr)
-    {
+    if (_current->next() == nullptr) {
         // TODO: remove throw
         throw std::logic_error("Statement::iterator::operator++() m_current->next() is nullptr");
     }
@@ -40,9 +39,7 @@ Scope::iterator& Scope::iterator::operator++(int)
 Statement& Scope::iterator::operator*() const
 {
     if (_current == nullptr)
-    {
         throw std::logic_error("Statement::iterator::operator*() m_current is nullptr");
-    }
 
     return *_current;
 }
@@ -76,9 +73,7 @@ Scope::~Scope() {
 Scope::iterator Scope::insert_after(Scope::iterator it, Statement::pointer statement)
 {
     if (statement == nullptr)
-    {
         throw std::invalid_argument("Statement::insert_after() cannot insert nullptr");
-    }
 
     statement->next(it->next());
     it->next(statement);
@@ -91,9 +86,7 @@ Scope::iterator Scope::insert_after(Scope::iterator it, Statement::pointer state
 Scope::iterator Scope::erase_after(Scope::iterator it)
 {
     if (it->next() == nullptr)
-    {
         return end();
-    }
 
     it->next(it->next()->next());
 
diff --git a/src/io/serializer.cpp b/src/io/serializer.cpp
new file mode 100644
index 0000000..6ebfa44
--- /dev/null
+++ b/src/io/serializer.cpp
@@ -0,0 +1,11 @@
+#include "io/serializer.h"
+
+Serializer::Serializer()
+{
+
+}
+
+Serializer::~Serializer()
+{
+
+}
diff --git a/src/ui/mainwindow.cpp b/src/ui/mainwindow.cpp
index 5a60391..5776db7 100644
--- a/src/ui/mainwindow.cpp
+++ b/src/ui/mainwindow.cpp
@@ -1,17 +1,22 @@
-#include "ui/mainwindow.h"
-#include "ui_mainwindow.h"
+#include "debugtools.h"
 
 #include "ui/metadatadialog.h"
+#include "ui/mainwindow.h"
+#include "ui_mainwindow.h"
 
 #include <iostream>
 
+#include <QMessageBox>
+#include <QFileDialog>
+
 MainWindow::MainWindow(samb::Structogram *structogram, QWidget *parent) :
     QMainWindow(parent),
     _ui(new Ui::MainWindow),
     _structogram(structogram)
 {
     _ui->setupUi(this);
-    initData();
+
+    toolButtonsEnabled((_structogram != nullptr));
 }
 
 MainWindow::~MainWindow()
@@ -24,43 +29,117 @@ MainWindow::~MainWindow()
 void MainWindow::on_newButton_clicked()
 {
     if (_structogram != nullptr)
-    {
-        // TODO: implement save dialog
-        std::cout << "TODO: implement save dialog" << std::endl;
+        if (!askSaveDialog())
+            return;
 
-        delete _structogram;
-        _structogram = nullptr;
-    }
+    delete _structogram;
+    _structogram = nullptr;
 
     MetadataDialog *dialog = new MetadataDialog(this);
-    if (dialog->exec() == QDialog::Accepted)
-    {
+    if (dialog->exec() == QDialog::Accepted) {
         _structogram = new samb::Structogram(dialog->title(), dialog->author());
+        toolButtonsEnabled(true);
+    } else {
+        toolButtonsEnabled(false);
     }
 
     delete dialog;
 }
 
+void MainWindow::on_openButton_clicked()
+{
+    if (_structogram != nullptr)
+        if (!askSaveDialog())
+            return;
+
+    QString fileName = QFileDialog::getOpenFileName(this,
+        tr("Load diagram"), "", "NS Diagram (*.nsdg);;All Files (*)");
+
+    if (fileName.isEmpty())
+        return;
+
+    debug_err("load dialog is unimplemented");
+
+    // toolButtonsEnabled(true);
+}
+
+void MainWindow::on_saveButton_clicked()
+{
+    QString fileName = QFileDialog::getSaveFileName(this,
+        tr("Save diagram"), "", tr("NS Diagram (*.nsdg);;All Files (*)"));
+
+    if (fileName.isEmpty())
+        return;
+
+    debug_err("saved dialog is unimplemented");
+
+    // toolButtonsEnabled(true);
+}
+
+void MainWindow::on_refreshButton_clicked()
+{
+
+}
+
 void MainWindow::on_metadataButton_clicked()
 {
-    if (_structogram == nullptr) { return; }
+    if (_structogram == nullptr)
+        return;
 
     MetadataDialog *dialog = new MetadataDialog(this);
     dialog->setMetadata(_structogram->title(), _structogram->author());
 
-    if (dialog->exec() == QDialog::Accepted)
-    {
+    if (dialog->exec() == QDialog::Accepted) {
         _structogram->title(dialog->title());
         _structogram->author(dialog->author());
     }
 }
 
+void MainWindow::on_newStatementButton_clicked()
+{
+
+}
+
 /**** private methods ****/
 
-void MainWindow::initData()
+/* @brief open a save dialog
+ * @return true if operation completed successfully
+ */
+bool MainWindow::askSaveDialog()
 {
-    if (_structogram == nullptr)
-    {
-        _structogram = new samb::Structogram("", "");
+    // TODO: check if it has already been saved once
+    auto reply = QMessageBox::question(this,
+                                       "Save " + _structogram->title(),
+                                       "'" + _structogram->title() + "' is not saved.\nDo you want to save it?",
+                                       QMessageBox::Save, QMessageBox::Discard);
+
+    if (reply == QMessageBox::Save) {
+        on_saveButton_clicked();
+
+        // TODO: check if file has been ACTUALLY saved
+        return true;
+    } else {
+        return true;
+    }
+
+}
+
+/* @brief control ui elements that are relate to _structogram member
+ */
+void MainWindow::toolButtonsEnabled(bool state)
+{
+    if (_structogram == nullptr && state == true) {
+        debug_err("called enableToolButtons(true) but _structogram is nullptr");
+        return;
     }
+
+    // buttons
+    _ui->refreshButton->setEnabled(state);
+    _ui->metadataButton->setEnabled(state);
+    _ui->newStatementButton->setEnabled(state);
+
+    // actions
+    _ui->actionSave->setEnabled(state);
+    _ui->actionSaveAs->setEnabled(state);
+    _ui->actionClose->setEnabled(state);
 }
diff --git a/src/ui/metadatadialog.cpp b/src/ui/metadatadialog.cpp
index 348f225..1235603 100644
--- a/src/ui/metadatadialog.cpp
+++ b/src/ui/metadatadialog.cpp
@@ -1,11 +1,22 @@
 #include "ui/metadatadialog.h"
 #include "ui_metadatadialog.h"
 
+#include "debugtools.h"
+#include <QPushButton>
+
 MetadataDialog::MetadataDialog(QWidget *parent) :
     QDialog(parent),
     _ui(new Ui::MetadataDialog)
 {
     _ui->setupUi(this);
+
+    QPushButton *button = _ui->buttonBox->button(QDialogButtonBox::Ok);
+
+    if (button != 0) {
+        button->setEnabled(false);
+    } else {
+        debug_err("failed to get ok button");
+    }
 }
 
 MetadataDialog::~MetadataDialog()
@@ -13,6 +24,14 @@ MetadataDialog::~MetadataDialog()
     delete _ui;
 }
 
+/*** public methods ***/
+
+bool MetadataDialog::isValid() const
+{
+    return !title().trimmed().isEmpty()
+            && !author().trimmed().isEmpty();
+}
+
 void MetadataDialog::setMetadata(const QString& title, const QString& author)
 {
     _ui->titleEdit->setText(title);
@@ -29,3 +48,29 @@ QString MetadataDialog::author() const
 {
     return _ui->authorEdit->text();
 }
+
+/*** private slots ***/
+
+void MetadataDialog::on_titleEdit_textChanged()
+{
+    QPushButton *button = _ui->buttonBox->button(QDialogButtonBox::Ok);
+
+    if (button == 0) {
+        debug_err("failed to get ok button");
+        return;
+    }
+
+    button->setEnabled(isValid());
+}
+
+void MetadataDialog::on_authorEdit_textChanged()
+{
+    QPushButton *button = _ui->buttonBox->button(QDialogButtonBox::Ok);
+
+    if (button == 0) {
+        debug_err("failed to get ok button");
+        return;
+    }
+
+    button->setEnabled(isValid());
+}