Xcode - Duplicate Line key binding

duplicate_line_xcode.md

Xcode line duplication (without overwriting your clipboard)

I find this shortcut extremely useful in Xcode: duplicate one or several lines without losing what you have on the clipboard.

Bind keys to duplicate lines in Xcode

1. To add custom key bindings in Xcode, you have to edit this file (su privileges required): /Applications/Xcode.app/Contents/Frameworks/IDEKit.framework/Versions/Current/Resources/IDETextKeyBindingSet.plist

I add the following new key at the bottom:

<key>User</key>
<dict>
    <key>Duplicate Lines Down</key>
    <string>selectParagraph:, delete:, yank:, moveToBeginningOfParagraph:, yankAndSelect:</string>
    <key>Duplicate Lines Up</key>
    <string>selectParagraph:, delete:, yankAndSelect:, moveToBeginningOfText:, yankAndSelect:</string>
    <key>Delete Line</key>
    <string>selectLine:, deleteBackward:</string>
</dict>

1. Open Xcode and go to Xcode Preferences -> Key Bindings
2. filter for Duplicate Lines Down, add a shortcut for it. I use the chord shift + alt + ↓, similar to the default from VSCode.
3. filter for Duplicate Lines Up, add a shortcut for it. I use the chord shift + alt + ↑, similar to the default from VSCode.
4. filter for Delete line, add a shortcut for it. I use the chord shift + alt + backspace

NOTE: you will have to do this every time Xcode is updated -- that's why you might as well write a shell script to automate most of it.

Automatization

NOTE: you will have to do this every time Xcode is updated -- that's why you might as well write a shell script to automate it.

I'm not doing a full automatization yet... I like doing the last step manually.

Save the following in bash shell script (I called it prepareXcodeKeybindingsForEditing.sh) and then call it from terminal with sudo sh prepareXcodeKeybindingsForEditing.sh everytime you update Xcode. It opens an editor (atom in my case, edit to your liking...) and prints the XML you need to copy-paste for you in terminal.

path='/Applications/Xcode.app/Contents/Frameworks/IDEKit.framework/Versions/Current/Resources/'
bindingsFile=$path'IDETextKeyBindingSet.plist'

sudo chmod 755 $path

if [ ! -f $bindingsFile ]; then
    echo "Bindings file doen't exist"
fi
sudo chmod 664 $bindingsFile
sudo open -a atom $bindingsFile

echo "Now paste the following:"
echo "<key>User</key>
<dict>
    <key>Duplicate Lines Down</key>
    <string>selectParagraph:, delete:, yank:, moveToBeginningOfParagraph:, yankAndSelect:</string>
    <key>Duplicate Lines Up</key>
    <string>selectParagraph:, delete:, yankAndSelect:, moveToBeginningOfText:, yankAndSelect:</string>
    <key>Delete Line</key>
    <string>selectLine:, deleteBackward:</string>
</dict>
```"
echo ""