From 3bd96f29d2d42a6cc99da530cbc900ac8176d4ce Mon Sep 17 00:00:00 2001
From: Cameron Youell <cameronyouell@gmail.com>
Date: Mon, 23 Jan 2023 14:11:01 +1100
Subject: [PATCH] Ladybird: Add LocationEdit Highlighting

---
 Ladybird/LocationEdit.cpp | 72 +++++++++++++++++++++++++++++++++++++--
 Ladybird/LocationEdit.h   | 10 ++++--
 2 files changed, 76 insertions(+), 6 deletions(-)

diff --git a/Ladybird/LocationEdit.cpp b/Ladybird/LocationEdit.cpp
index 474a3fd0634..61489c0b16b 100644
--- a/Ladybird/LocationEdit.cpp
+++ b/Ladybird/LocationEdit.cpp
@@ -5,12 +5,78 @@
  */
 
 #include "LocationEdit.h"
-#include "Tab.h"
+#include "Utilities.h"
+#include <AK/URL.h>
+#include <QCoreApplication>
+#include <QPalette>
+#include <QTextLayout>
 
-LocationEdit::LocationEdit(Tab* tab)
-    : QLineEdit(tab)
+LocationEdit::LocationEdit(QWidget* parent)
+    : QLineEdit(parent)
 {
     connect(this, &QLineEdit::returnPressed, this, [&] {
         clearFocus();
     });
+
+    connect(this, &QLineEdit::textChanged, this, [&] {
+        highlight_location();
+    });
+}
+
+void LocationEdit::focusInEvent(QFocusEvent* event)
+{
+    QLineEdit::focusInEvent(event);
+    highlight_location();
+}
+
+void LocationEdit::focusOutEvent(QFocusEvent* event)
+{
+    QLineEdit::focusOutEvent(event);
+    highlight_location();
+}
+
+void LocationEdit::highlight_location()
+{
+    auto url = AK::URL::create_with_url_or_path(ak_deprecated_string_from_qstring(text()));
+
+    QList<QInputMethodEvent::Attribute> attributes;
+    if (url.is_valid() && !hasFocus()) {
+        if (url.scheme() == "http" || url.scheme() == "https" || url.scheme() == "gemini") {
+            int host_start = (url.scheme().length() + 3) - cursorPosition();
+            auto host_length = url.host().length();
+
+            // FIXME: Maybe add a generator to use https://publicsuffix.org/list/public_suffix_list.dat
+            //        for now just highlight the whole host
+
+            QTextCharFormat defaultFormat;
+            defaultFormat.setForeground(QPalette().color(QPalette::PlaceholderText));
+            attributes.append({
+                QInputMethodEvent::TextFormat,
+                -cursorPosition(),
+                static_cast<int>(text().length()),
+                defaultFormat,
+            });
+
+            QTextCharFormat hostFormat;
+            hostFormat.setForeground(QPalette().color(QPalette::Text));
+            attributes.append({
+                QInputMethodEvent::TextFormat,
+                host_start,
+                static_cast<int>(host_length),
+                hostFormat,
+            });
+        } else if (url.scheme() == "file") {
+            QTextCharFormat schemeFormat;
+            schemeFormat.setForeground(QPalette().color(QPalette::PlaceholderText));
+            attributes.append({
+                QInputMethodEvent::TextFormat,
+                -cursorPosition(),
+                static_cast<int>(url.scheme().length() + 3),
+                schemeFormat,
+            });
+        }
+    }
+
+    QInputMethodEvent event(QString(), attributes);
+    QCoreApplication::sendEvent(this, &event);
 }
diff --git a/Ladybird/LocationEdit.h b/Ladybird/LocationEdit.h
index d8ebda54900..20ed6771f19 100644
--- a/Ladybird/LocationEdit.h
+++ b/Ladybird/LocationEdit.h
@@ -10,10 +10,14 @@
 
 #include <QLineEdit>
 
-class Tab;
-
 class LocationEdit final : public QLineEdit {
     Q_OBJECT
 public:
-    explicit LocationEdit(Tab*);
+    explicit LocationEdit(QWidget*);
+
+private:
+    virtual void focusInEvent(QFocusEvent* event) override;
+    virtual void focusOutEvent(QFocusEvent* event) override;
+
+    void highlight_location();
 };