Allow setting the color of the rendered link

Qt does not use the QPalette::Link color when rendering rich text.
Therefore, we do it directly via the style-attribute of the <a> tag.

GnuPG-bug-id: 5535

src/view/urllabel.cpp

@@ -13,28 +13,69 @@
 #include "urllabel.h"
 
 #include <QAccessible>
+#include <QPalette>
 
 using namespace Kleo;
 
-UrlLabel::UrlLabel(QWidget *parent)
-    : QLabel{parent}
+class UrlLabel::Private
 {
-    setTextFormat(Qt::RichText);
-    setTextInteractionFlags(Qt::TextBrowserInteraction);
-}
+    UrlLabel *q;
+public:
+    Private(UrlLabel *q) : q{q} {}
 
-void UrlLabel::setUrl(const QUrl &url, const QString &text)
+    void ensureLinkColorIsValid();
+    void updateLabel();
+
+    QUrl url;
+    QString text;
+    QColor linkColor;
+};
+
+void UrlLabel::Private::ensureLinkColorIsValid()
+{
+    if (!linkColor.isValid()) {
+        linkColor = q->palette().link().color();
+    }
+}
+void UrlLabel::Private::updateLabel()
 {
     // we prepend a zero-width-space character to work around a bug in QLabel::focusNextPrevChild(false)
     // which makes it impossible to leave the label with Shift+Tab if the text starts with a link
-    static const QString templateString{QLatin1String{"&#8203;<a href=\"%1\">%2</a>"}};
+    static const QString templateString{QLatin1String{"&#8203;<a style=\"color: %1;\" href=\"%2\">%3</a>"}};
 
     if (url.isEmpty()) {
-        clear();
+        q->clear();
         return;
     }
 
-    setText(templateString.arg(url.url(QUrl::FullyEncoded), text.isEmpty() ? url.toDisplayString().toHtmlEscaped() : text.toHtmlEscaped()));
+    ensureLinkColorIsValid();
+    q->setText(templateString.arg(
+        linkColor.name(),
+        url.url(QUrl::FullyEncoded),
+        text.isEmpty() ? url.toDisplayString().toHtmlEscaped() : text.toHtmlEscaped()));
+}
+
+UrlLabel::UrlLabel(QWidget *parent)
+    : QLabel{parent}
+    , d{new Private{this}}
+{
+    setTextFormat(Qt::RichText);
+    setTextInteractionFlags(Qt::TextBrowserInteraction);
+}
+
+Kleo::UrlLabel::~UrlLabel() = default;
+
+void UrlLabel::setUrl(const QUrl &url, const QString &text)
+{
+    d->url = url;
+    d->text = text;
+    d->updateLabel();
+}
+
+void UrlLabel::setLinkColor(const QColor &color)
+{
+    d->linkColor = color;
+    d->updateLabel();
 }
 
 void UrlLabel::focusInEvent(QFocusEvent *event)

src/view/urllabel.h

@@ -12,6 +12,8 @@
 
 #include <QLabel>
 
+#include <memory>
+
 namespace Kleo
 {
 
@@ -20,15 +22,22 @@ class UrlLabel : public QLabel
     Q_OBJECT
 public:
     explicit UrlLabel(QWidget *parent = nullptr);
+    ~UrlLabel() override;
 
     void setUrl(const QUrl &url, const QString &text = {});
 
+    void setLinkColor(const QColor &color);
+
 protected:
     void focusInEvent(QFocusEvent *event) override;
     bool focusNextPrevChild(bool next) override;
 
 private:
     using QLabel::setText;
+
+private:
+    class Private;
+    std::unique_ptr<Private> d;
 };
 
 }