Add keyboard shorcuts to focus and unfocus chat (#3898)

* Added keyboard shorcuts to focus and unfocus chat

* Fixed format

* Changed the Esc behavior to work on any QLineEdit in the main Window and ignore shortcut conflicts

* Fixed a conflict with shortcuts

* Configurable unfocus shortcut and format fixes

* minor style fix

cockatrice/src/customlineedit.cpp

@@ -0,0 +1,72 @@
+
+#include "customlineedit.h"
+
+#include "settingscache.h"
+#include "shortcutssettings.h"
+
+#include <QKeyEvent>
+#include <QLineEdit>
+#include <QObject>
+#include <QWidget>
+
+LineEditUnfocusable::LineEditUnfocusable(QWidget *parent) : QLineEdit(parent)
+{
+    installEventFilter(this);
+}
+
+LineEditUnfocusable::LineEditUnfocusable(const QString &contents, QWidget *parent) : QLineEdit(contents, parent)
+{
+    installEventFilter(this);
+}
+
+bool LineEditUnfocusable::isUnfocusShortcut(QKeyEvent *event)
+{
+    QString modifier;
+    QString keyNoMod;
+
+    if (event->modifiers() & Qt::ShiftModifier)
+        modifier += "Shift+";
+    if (event->modifiers() & Qt::ControlModifier)
+        modifier += "Ctrl+";
+    if (event->modifiers() & Qt::AltModifier)
+        modifier += "Alt+";
+    if (event->modifiers() & Qt::MetaModifier)
+        modifier += "Meta+";
+
+    keyNoMod = QKeySequence(event->key()).toString();
+
+    QKeySequence key(modifier + keyNoMod);
+    QList<QKeySequence> unfocusShortcut = settingsCache->shortcuts().getShortcut("Textbox/unfocusTextBox");
+
+    for (QList<QKeySequence>::iterator i = unfocusShortcut.begin(); i != unfocusShortcut.end(); ++i) {
+        if (key.matches(*i) == QKeySequence::ExactMatch)
+            return true;
+    }
+    return false;
+}
+
+void LineEditUnfocusable::keyPressEvent(QKeyEvent *event)
+{
+    if (isUnfocusShortcut(event)) {
+        clearFocus();
+
+        return;
+    }
+
+    QLineEdit::keyPressEvent(event);
+}
+
+bool LineEditUnfocusable::eventFilter(QObject *watched, QEvent *event)
+{
+    if (event->type() == QEvent::ShortcutOverride) {
+        QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
+
+        if (isUnfocusShortcut(keyEvent)) {
+            event->accept();
+
+            return true;
+        }
+    }
+
+    return QLineEdit::eventFilter(watched, event);
+}