NOISSUE use model/view for Minecraft log data

application/widgets/LogView.cpp

@@ -0,0 +1,143 @@
+#include "LogView.h"
+#include <QTextBlock>
+#include <QScrollBar>
+
+LogView::LogView(QWidget* parent) : QPlainTextEdit(parent)
+{
+	setWordWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
+	m_defaultFormat = new QTextCharFormat(currentCharFormat());
+}
+
+LogView::~LogView()
+{
+}
+
+void LogView::setWordWrap(bool wrapping)
+{
+	if(wrapping)
+	{
+		setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+		setLineWrapMode(QPlainTextEdit::WidgetWidth);
+	}
+	else
+	{
+		setHorizontalScrollBarPolicy(Qt::ScrollBarAsNeeded);
+		setLineWrapMode(QPlainTextEdit::NoWrap);
+	}
+}
+
+void LogView::setModel(QAbstractItemModel* model)
+{
+	if(m_model)
+	{
+		disconnect(m_model, &QAbstractItemModel::modelReset, this, &LogView::repopulate);
+		disconnect(m_model, &QAbstractItemModel::rowsInserted, this, &LogView::rowsInserted);
+		disconnect(m_model, &QAbstractItemModel::rowsAboutToBeInserted, this, &LogView::rowsAboutToBeInserted);
+		disconnect(m_model, &QAbstractItemModel::rowsRemoved, this, &LogView::rowsRemoved);
+	}
+	m_model = model;
+	if(m_model)
+	{
+		connect(m_model, &QAbstractItemModel::modelReset, this, &LogView::repopulate);
+		connect(m_model, &QAbstractItemModel::rowsInserted, this, &LogView::rowsInserted);
+		connect(m_model, &QAbstractItemModel::rowsAboutToBeInserted, this, &LogView::rowsAboutToBeInserted);
+		connect(m_model, &QAbstractItemModel::rowsRemoved, this, &LogView::rowsRemoved);
+		connect(m_model, &QAbstractItemModel::destroyed, this, &LogView::modelDestroyed);
+	}
+	repopulate();
+}
+
+QAbstractItemModel * LogView::model() const
+{
+	return m_model;
+}
+
+void LogView::modelDestroyed(QObject* model)
+{
+	if(m_model == model)
+	{
+		setModel(nullptr);
+	}
+}
+
+void LogView::repopulate()
+{
+	auto doc = document();
+	doc->clear();
+	if(!m_model)
+	{
+		return;
+	}
+	rowsInserted(QModelIndex(), 0, m_model->rowCount() - 1);
+}
+
+void LogView::rowsAboutToBeInserted(const QModelIndex& parent, int first, int last)
+{
+	Q_UNUSED(parent)
+	Q_UNUSED(first)
+	Q_UNUSED(last)
+	QScrollBar *bar = verticalScrollBar();
+	int max_bar = bar->maximum();
+	int val_bar = bar->value();
+	if (m_scroll)
+	{
+		m_scroll = (max_bar - val_bar) <= 1;
+	}
+	else
+	{
+		m_scroll = val_bar == max_bar;
+	}
+}
+
+void LogView::rowsInserted(const QModelIndex& parent, int first, int last)
+{
+	for(int i = first; i <= last; i++)
+	{
+		auto idx = m_model->index(i, 0, parent);
+		auto text = m_model->data(idx, Qt::DisplayRole).toString();
+		QTextCharFormat format(*m_defaultFormat);
+		auto font = m_model->data(idx, Qt::FontRole);
+		if(font.isValid())
+		{
+			format.setFont(font.value<QFont>());
+		}
+		auto fg = m_model->data(idx, Qt::TextColorRole);
+		if(fg.isValid())
+		{
+			format.setForeground(fg.value<QColor>());
+		}
+		auto bg = m_model->data(idx, Qt::BackgroundRole);
+		if(bg.isValid())
+		{
+			format.setBackground(bg.value<QColor>());
+		}
+		auto workCursor = textCursor();
+		workCursor.movePosition(QTextCursor::End);
+		workCursor.insertText(text, format);
+		workCursor.insertBlock();
+	}
+	if(m_scroll && !m_scrolling)
+	{
+		m_scrolling = true;
+		QMetaObject::invokeMethod( this, "scrollToBottom", Qt::QueuedConnection);
+	}
+}
+
+void LogView::rowsRemoved(const QModelIndex& parent, int first, int last)
+{
+	// TODO: some day... maybe
+	Q_UNUSED(parent)
+	Q_UNUSED(first)
+	Q_UNUSED(last)
+}
+
+void LogView::scrollToBottom()
+{
+	m_scrolling = false;
+	verticalScrollBar()->setSliderPosition(verticalScrollBar()->maximum());
+}
+
+void LogView::findNext(const QString& what, bool reverse)
+{
+	find(what, reverse ? QTextDocument::FindFlag::FindBackward : QTextDocument::FindFlag(0));
+}

application/widgets/LogView.h

@@ -0,0 +1,36 @@
+#pragma once
+#include <QPlainTextEdit>
+#include <QAbstractItemView>
+
+class QAbstractItemModel;
+
+class LogView: public QPlainTextEdit
+{
+	Q_OBJECT
+public:
+	explicit LogView(QWidget *parent = nullptr);
+	virtual ~LogView();
+
+	virtual void setModel(QAbstractItemModel *model);
+	QAbstractItemModel *model() const;
+
+public slots:
+	void setWordWrap(bool wrapping);
+	void findNext(const QString & what, bool reverse);
+	void scrollToBottom();
+
+protected slots:
+	void repopulate();
+	// note: this supports only appending
+	void rowsInserted(const QModelIndex &parent, int first, int last);
+	void rowsAboutToBeInserted(const QModelIndex &parent, int first, int last);
+	// note: this supports only removing from front
+	void rowsRemoved(const QModelIndex &parent, int first, int last);
+	void modelDestroyed(QObject * model);
+
+protected:
+	QAbstractItemModel *m_model = nullptr;
+	QTextCharFormat *m_defaultFormat = nullptr;
+	bool m_scroll = false;
+	bool m_scrolling = false;
+};