Let users with external keyboards send messages using modifier-return (shift, command, option).

// FREEBIE

Signal/src/ViewControllers/ConversationView/ConversationInputTextView.h

@@ -12,6 +12,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)inputTextViewDidBecomeFirstResponder;
 
+- (void)inputTextViewSendMessagePressed;
+
 @end
 
 #pragma mark -

Signal/src/ViewControllers/ConversationView/ConversationInputTextView.m

@@ -196,6 +196,48 @@ NS_ASSUME_NONNULL_BEGIN
     [textView resignFirstResponder];
 }
 
+#pragma mark - Key Commands
+
+- (nullable NSArray<UIKeyCommand *> *)keyCommands
+{
+    // We're permissive about what modifier key we accept for the "send message" hotkey.
+    // We accept command-return, option-return and shift-return.  We don't support
+    // control-return because it doesn't work.
+    return @[
+        [UIKeyCommand keyCommandWithInput:@"\r"
+                            modifierFlags:UIKeyModifierShift
+                                   action:@selector(modifiedReturnPressed:)
+                     discoverabilityTitle:@"Send Message"],
+        [UIKeyCommand keyCommandWithInput:@"\r"
+                            modifierFlags:UIKeyModifierCommand
+                                   action:@selector(modifiedReturnPressed:)
+                     discoverabilityTitle:@"Send Message"],
+        // "Alternate" is option.
+        [UIKeyCommand keyCommandWithInput:@"\r"
+                            modifierFlags:UIKeyModifierAlternate
+                                   action:@selector(modifiedReturnPressed:)
+                     discoverabilityTitle:@"Send Message"],
+    ];
+}
+
+- (void)modifiedReturnPressed:(UIKeyCommand *)sender
+{
+    DDLogInfo(@"%@ modifiedReturnPressed: %@", self.logTag, sender.input);
+    [self.inputTextViewDelegate inputTextViewSendMessagePressed];
+}
+
+#pragma mark - Logging
+
++ (NSString *)logTag
+{
+    return [NSString stringWithFormat:@"[%@]", self.class];
+}
+
+- (NSString *)logTag
+{
+    return self.class.logTag;
+}
+
 @end
 
 NS_ASSUME_NONNULL_END

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -3443,6 +3443,11 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
     [self scrollToBottomAnimated:YES];
 }
 
+- (void)inputTextViewSendMessagePressed
+{
+    [self sendButtonPressed];
+}
+
 - (void)didPasteAttachment:(SignalAttachment *_Nullable)attachment
 {
     DDLogError(@"%@ %s", self.tag, __PRETTY_FUNCTION__);