Add a Send button that can be used to send messages (#4607)

This button is disabled by default, and can be enabled with the "Show send message button" setting.

src/widgets/settingspages/GeneralPage.cpp

@@ -1014,6 +1014,11 @@ void GeneralPage::initLayout(GeneralPageView &layout)
     helixTimegateModerators->setMinimumWidth(
         helixTimegateModerators->minimumSizeHint().width());
 
+    layout.addCheckbox(
+        "Show send message button", s.showSendButton, false,
+        "Show a Send button next to each split input that can be "
+        "clicked to send the message");
+
     layout.addStretch();
 
     // invisible element for width

src/widgets/splits/SplitInput.cpp

@@ -1,6 +1,7 @@
 #include "widgets/splits/SplitInput.hpp"
 
 #include "Application.hpp"
+#include "common/enums/MessageOverflow.hpp"
 #include "common/QLogging.hpp"
 #include "controllers/commands/CommandController.hpp"
 #include "controllers/hotkeys/HotkeyController.hpp"
@@ -114,6 +115,28 @@ void SplitInput::initLayout()
     connect(textEdit.getElement(), &ResizingTextEdit::textChanged, this,
             &SplitInput::editTextChanged);
 
+    hboxLayout.emplace<EffectLabel>().assign(&this->ui_.sendButton);
+    this->ui_.sendButton->getLabel().setText("SEND");
+    this->ui_.sendButton->hide();
+
+    QObject::connect(this->ui_.sendButton, &EffectLabel::leftClicked, [this] {
+        std::vector<QString> arguments;
+        this->handleSendMessage(arguments);
+    });
+
+    getSettings()->showSendButton.connect(
+        [this](const bool value, auto) {
+            if (value)
+            {
+                this->ui_.sendButton->show();
+            }
+            else
+            {
+                this->ui_.sendButton->hide();
+            }
+        },
+        this->managedConnections_);
+
     // right box
     auto box = hboxLayout.emplace<QVBoxLayout>().withoutMargin();
     box->setSpacing(0);

src/widgets/splits/SplitInput.hpp

@@ -23,19 +23,6 @@ class MessageThread;
 class ResizingTextEdit;
 class ChannelView;
 
-// MessageOverflow is used for controlling how to guide the user into not
-// sending a message that will be discarded by Twitch
-enum MessageOverflow {
-    // Allow overflowing characters to be inserted into the input box, but highlight them in red
-    Highlight,
-
-    // Prevent more characters from being inserted into the input box
-    Prevent,
-
-    // Do nothing
-    Allow,
-};
-
 class SplitInput : public BaseWidget
 {
     Q_OBJECT
@@ -132,6 +119,7 @@ protected:
     struct {
         ResizingTextEdit *textEdit;
         QLabel *textEditLength;
+        EffectLabel *sendButton;
         EffectLabel *emoteButton;
 
         QHBoxLayout *hbox;