Add URL syntax highlighting. https://redmine.stoutner.com/issues/1024

[PrivacyBrowserPC.git] / src / widgets / UrlLineEdit.cpp

diff --git a/src/widgets/UrlLineEdit.cpp b/src/widgets/UrlLineEdit.cpp
new file mode 100644 (file)
index 0000000..a06cf97
--- /dev/null
+++ b/src/widgets/UrlLineEdit.cpp
@@ -0,0 +1,108 @@
+/*
+ * Copyright 2024 Soren Stoutner <soren@stoutner.com>.
+ *
+ * This file is part of Privacy Browser PC <https://www.stoutner.com/privacy-browser-pc>.
+ *
+ * Privacy Browser PC is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Privacy Browser PC is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Privacy Browser PC.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+// Application headers.
+#include "UrlLineEdit.h"
+
+// Qt toolkit headers.
+#include <QInputMethodEvent>
+
+// Construct the class.
+UrlLineEdit::UrlLineEdit(QWidget *parentWidgetPointer) : KLineEdit(parentWidgetPointer) {}
+
+void UrlLineEdit::focusInEvent(QFocusEvent *focusEventPointer)
+{
+    // Create an input method event attribute list.
+    QList<QInputMethodEvent::Attribute> inputMethodEventAttributeList;
+
+    // Create an input method event with no formatting.
+    QInputMethodEvent inputMethodEvent(QString(QLatin1String("")), inputMethodEventAttributeList);
+
+    // Apply the empty formatting to remove the URL highlighting.
+    event(&inputMethodEvent);
+
+    // Run the default commands.
+    KLineEdit::focusInEvent(focusEventPointer);
+}
+
+void UrlLineEdit::focusOutEvent(QFocusEvent *focusEventPointer)
+{
+    // Reapply the highlight to the current text.
+    setText(text());
+
+    // Run the default commands.
+    KLineEdit::focusOutEvent(focusEventPointer);
+}
+
+void UrlLineEdit::setText(const QString &urlString)
+{
+    // Wipe the currently displayed text.
+    KLineEdit::setText(QLatin1String(""));
+
+    // Create an input method event attribute list.
+    QList<QInputMethodEvent::Attribute> inputMethodEventAttributeList;
+
+    // Calculate the URL string length.
+    int urlStringLength = urlString.length();
+
+    // Get the index of end of the schema.
+    int endOfSchemaIndex = urlString.indexOf(QLatin1String("//")) + 2;
+
+    // Get the index of the last `.` in the domain.
+    int lastDotIndex = urlString.lastIndexOf(QLatin1Char('.'));
+
+    // Get the index of the penultimate `.` in the domain.  If this doesn't exist it will be set to `-1`.
+    int penultimateDotIndex = urlString.lastIndexOf(QLatin1Char('.'), lastDotIndex - urlStringLength - 1);
+
+    // Get the index of the `/` immediately after the domain name.  If this doesn't exit it will be set to `-1`.
+    int endOfDomainNameIndex = urlString.indexOf(QLatin1Char('/'), endOfSchemaIndex);
+
+    // Create the text character formats.
+    QTextCharFormat grayTextCharFormat;
+    QTextCharFormat schemaTextCharFormat;
+
+    // Set the text character format colors.
+    grayTextCharFormat.setForeground(Qt::darkGray);
+
+    // Set the schema text character format color.
+    if (urlString.startsWith(QLatin1String("http://")) || urlString.startsWith(QLatin1String("view-source:http://")))
+        schemaTextCharFormat.setForeground(Qt::red);
+    else
+        schemaTextCharFormat = grayTextCharFormat;
+
+    // Append the schema text format format.
+    inputMethodEventAttributeList.append(QInputMethodEvent::Attribute(QInputMethodEvent::TextFormat, 0, endOfSchemaIndex, schemaTextCharFormat));
+
+    // Append the subdomain format if the subdomain exists.  If it doesn't, the penultimate dot index will be `-1`.
+    if (penultimateDotIndex > 0)
+        inputMethodEventAttributeList.append(QInputMethodEvent::Attribute(QInputMethodEvent::TextFormat, endOfSchemaIndex, penultimateDotIndex + 1 - endOfSchemaIndex, grayTextCharFormat));
+
+    // Append the post domain formatting if text exists after the domain name.  If it doesn't, the end of domain name index will be `-1`.
+    if (endOfDomainNameIndex > 0)
+        inputMethodEventAttributeList.append(QInputMethodEvent::Attribute(QInputMethodEvent::TextFormat, endOfDomainNameIndex, urlStringLength - endOfDomainNameIndex, grayTextCharFormat));
+
+    // Create an input method event with an empty pre-edit string.
+    QInputMethodEvent inputMethodEvent(QString(""), inputMethodEventAttributeList);
+
+    // Apply the URL highlighting.
+    event(&inputMethodEvent);
+
+    // Run the default commands.
+    KLineEdit::setText(urlString);
+}