Add settings toggle for scroll-to-input

Adds a "Scroll to send input" preference under Settings → External
Keyboard → Scrolling, defaulting to off. When disabled, touch
scrolling uses the original scrollback-only behavior.

Author: splch

app/AboutExternalKeyboardViewController.m

@@ -17,6 +17,7 @@ @interface AboutExternalKeyboardViewController ()
 @property (weak, nonatomic) IBOutlet UISwitch *backtickEscapeSwitch;
 @property (weak, nonatomic) IBOutlet UISwitch *overrideControlSpaceSwitch;
 @property (weak, nonatomic) IBOutlet UISwitch *hideExtraKeysWithExternalKeyboardSwitch;
+@property (weak, nonatomic) IBOutlet UISwitch *scrollToSendInputSwitch;
 
 @end
 
@@ -38,6 +39,7 @@ - (void)_update {
     self.backtickEscapeSwitch.on = UserPreferences.shared.backtickMapEscape;
     self.overrideControlSpaceSwitch.on = UserPreferences.shared.overrideControlSpace;
     self.hideExtraKeysWithExternalKeyboardSwitch.on = UserPreferences.shared.hideExtraKeysWithExternalKeyboard;
+    self.scrollToSendInputSwitch.on = UserPreferences.shared.scrollToSendInput;
 }
 
 - (IBAction)optionMetaToggle:(UISwitch *)sender {
@@ -52,6 +54,9 @@ - (IBAction)overrideControlSpaceToggle:(UISwitch *)sender {
 - (IBAction)hideExtraKeysToggle:(UISwitch *)sender {
     UserPreferences.shared.hideExtraKeysWithExternalKeyboard = sender.on;
 }
+- (IBAction)scrollToSendInputToggle:(UISwitch *)sender {
+    UserPreferences.shared.scrollToSendInput = sender.on;
+}
 
 - (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
     if (indexPath.section == kCapsLockMappingSection && cell.tag == UserPreferences.shared.capsLockMapping)

app/Base.lproj/About.storyboard

@@ -600,6 +600,39 @@
                                     </tableViewCell>
                                 </cells>
                             </tableViewSection>
+                            <tableViewSection headerTitle="Scrolling" footerTitle="Sends scroll gestures as input to programs like tmux, less, and vim instead of scrolling the terminal buffer." id="sSi-7k-RmQ">
+                                <cells>
+                                    <tableViewCell clipsSubviews="YES" contentMode="scaleToFill" preservesSuperviewLayoutMargins="YES" selectionStyle="none" indentationWidth="10" id="qLs-3v-Kx9" userLabel="Scroll To Send Input">
+                                        <rect key="frame" x="0.0" y="560" width="320" height="43.5"/>
+                                        <autoresizingMask key="autoresizingMask"/>
+                                        <tableViewCellContentView key="contentView" opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center" preservesSuperviewLayoutMargins="YES" insetsLayoutMarginsFromSafeArea="NO" tableViewCell="qLs-3v-Kx9" id="bNe-4h-Yw2">
+                                            <rect key="frame" x="0.0" y="0.0" width="320" height="43.5"/>
+                                            <autoresizingMask key="autoresizingMask"/>
+                                            <subviews>
+                                                <label opaque="NO" multipleTouchEnabled="YES" contentMode="left" insetsLayoutMarginsFromSafeArea="NO" text="Scroll to send input" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="pXw-5m-Rj3">
+                                                    <rect key="frame" x="16" y="11.5" width="160" height="21"/>
+                                                    <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                                                    <nil key="textColor"/>
+                                                    <nil key="highlightedColor"/>
+                                                </label>
+                                                <switch opaque="NO" contentMode="scaleToFill" horizontalHuggingPriority="750" verticalHuggingPriority="750" contentHorizontalAlignment="center" contentVerticalAlignment="center" translatesAutoresizingMaskIntoConstraints="NO" id="mVt-8c-Zw1">
+                                                    <rect key="frame" x="255" y="6.5" width="51" height="31"/>
+                                                    <connections>
+                                                        <action selector="scrollToSendInputToggle:" destination="Zzy-IN-laJ" eventType="valueChanged" id="aKp-2n-Xf4"/>
+                                                    </connections>
+                                                </switch>
+                                            </subviews>
+                                            <constraints>
+                                                <constraint firstItem="pXw-5m-Rj3" firstAttribute="leading" secondItem="bNe-4h-Yw2" secondAttribute="leadingMargin" id="tRm-6k-Hq1"/>
+                                                <constraint firstItem="pXw-5m-Rj3" firstAttribute="centerY" secondItem="bNe-4h-Yw2" secondAttribute="centerY" id="uKp-3m-Wn7"/>
+                                                <constraint firstAttribute="trailingMargin" secondItem="mVt-8c-Zw1" secondAttribute="trailing" id="vQr-9p-Xs2"/>
+                                                <constraint firstItem="mVt-8c-Zw1" firstAttribute="centerY" secondItem="bNe-4h-Yw2" secondAttribute="centerY" id="wLn-4q-Yt8"/>
+                                                <constraint firstItem="mVt-8c-Zw1" firstAttribute="leading" relation="greaterThanOrEqual" secondItem="pXw-5m-Rj3" secondAttribute="trailing" constant="8" symbolic="YES" id="xMo-5r-Zu3"/>
+                                            </constraints>
+                                        </tableViewCellContentView>
+                                    </tableViewCell>
+                                </cells>
+                            </tableViewSection>
                         </sections>
                         <connections>
                             <outlet property="dataSource" destination="Zzy-IN-laJ" id="NPA-6F-jMj"/>
@@ -612,6 +645,7 @@
                         <outlet property="hideExtraKeysWithExternalKeyboardSwitch" destination="IcN-9M-x1K" id="Lw3-4l-9R6"/>
                         <outlet property="optionMetaSwitch" destination="OEG-YY-LTw" id="b2K-Ug-Jij"/>
                         <outlet property="overrideControlSpaceSwitch" destination="554-OF-h41" id="js8-8D-1Ua"/>
+                        <outlet property="scrollToSendInputSwitch" destination="mVt-8c-Zw1" id="rKs-6t-Bv5"/>
                     </connections>
                 </tableViewController>
                 <placeholder placeholderIdentifier="IBFirstResponder" id="XlH-jX-0dL" userLabel="First Responder" sceneMemberID="firstResponder"/>

app/TerminalView.m

@@ -275,7 +275,7 @@ - (void)scrollViewDidScroll:(UIScrollView *)scrollView {
 
     CGFloat delta = newY - _prevScrollY;
     _prevScrollY = newY;
-    if (delta != 0) {
+    if (delta != 0 && UserPreferences.shared.scrollToSendInput) {
         [self.terminal.webView evaluateJavaScript:[NSString stringWithFormat:@"exports.handleScrollDelta(%f)", delta] completionHandler:nil];
     }
 }

app/UserPreferences.h

@@ -52,6 +52,7 @@ extern NSString *const kThemeBackgroundColor;
 @property BOOL hideExtraKeysWithExternalKeyboard;
 @property BOOL overrideControlSpace;
 @property BOOL hideStatusBar;
+@property BOOL scrollToSendInput;
 @property (nonatomic) Theme *theme;
 @property (nonatomic) Palette *palette;
 @property BOOL shouldDisableDimming;

app/UserPreferences.m

@@ -25,6 +25,7 @@
 static NSString *const kPreferenceCursorStyleKey = @"Cursor Style";
 static NSString *const kPreferenceBlinkCursorKey = @"Blink Cursor";
 NSString *const kPreferenceHideStatusBarKey = @"Status Bar";
+static NSString *const kPreferenceScrollToSendInputKey = @"Scroll To Send Input";
 static NSString *const kPreferenceColorSchemeKey = @"Color Scheme";
 // This key has a different naming scheme because it's used in UI tests as a
 // CLI argument.
@@ -165,6 +166,7 @@ - (instancetype)init {
             kPreferenceBlinkCursorKey: @(NO),
             kPreferenceCursorStyleKey: @(CursorStyleBlock),
             kPreferenceHideStatusBarKey: @(NO),
+            kPreferenceScrollToSendInputKey: @(NO),
             kPreferenceColorSchemeKey: @(ColorSchemeMatchSystem),
             kPreferenceThemeKey: @"Default",
             kHostnameOverrideKey: UIDevice.currentDevice.name,
@@ -202,6 +204,7 @@ - (instancetype)init {
             @"color_scheme": kPreferenceColorSchemeKey,
             @"theme": kPreferenceThemeKey,
             @"hostname_override": kHostnameOverrideKey,
+            @"scroll_to_send_input": kPreferenceScrollToSendInputKey,
         };
         NSMutableDictionary <NSString *, NSString *> *reverseMapping = [NSMutableDictionary new];
         for (NSString *key in friendlyPreferenceMapping) {
@@ -225,6 +228,7 @@ - (instancetype)init {
             kPreferenceBlinkCursorKey: property(blinkCursor),
             kPreferenceHideStatusBarKey: property(hideStatusBar),
             kPreferenceColorSchemeKey: property(colorScheme),
+            kPreferenceScrollToSendInputKey: property(scrollToSendInput),
             // This one is a little bit special, so it needs extra handling.
             // The backing property for this is intentionally underscored.
             kPreferenceThemeKey: @"userTheme",
@@ -525,6 +529,19 @@ - (BOOL)validateHideStatusBar:(id *)value error:(NSError **)error {
     return [*value isKindOfClass:NSNumber.class];
 }
 
+// MARK: scrollToSendInput
+- (BOOL)scrollToSendInput {
+    return [_defaults boolForKey:kPreferenceScrollToSendInputKey];
+}
+
+- (void)setScrollToSendInput:(BOOL)scrollToSendInput {
+    [_defaults setBool:scrollToSendInput forKey:kPreferenceScrollToSendInputKey];
+}
+
+- (BOOL)validateScrollToSendInput:(id *)value error:(NSError **)error {
+    return [*value isKindOfClass:NSNumber.class];
+}
+
 // MARK: colorScheme
 - (ColorScheme)colorScheme {
     return [_defaults integerForKey:kPreferenceColorSchemeKey];