qCalc Code Editor Guide

qCalc Code Editor Guide
1. Where you use the editor
2. Writing calculator code in mycal
3. Evaluating an expression in eva
4. Editor features
5. Keyboard shortcuts
6. File and fullscreen controls

The qCalc code editor is used when you write Python code for a calculator in mycal or enter a Python expression in eva. It is a Python-aware editing surface designed to make code entry, correction, and reuse easier.

1. Where you use the editor

Use mycal to write a complete calculator function and its metadata function. Use eva when you want to evaluate a Python expression directly without creating and saving a calculator.

The editor does not replace qCalc's normal validation workflow. In mycal, use the available Check Syntax, Format Code, validation, and save actions after editing your code.

2. Writing calculator code in `mycal`

Create a calculator by defining a Python function and a matching __info() function. The main function contains the calculation; __info() supplies the calculator title and other form metadata.

def circle_area(radius=1.0):
    return pi * radius ** 2


def circle_area__info():
    return {
        "title": "Circle Area",
    }

The indentation in the example is important: statements inside a Python function are indented by four spaces. Select several lines and press Tab to indent them together, or Shift+Tab to remove one indentation level.

3. Evaluating an expression in `eva`

Use eva for a quick calculation or to experiment with a qCalc expression. For example:

Qty("10 m") + Qty("3 ft")

You can also enter a longer expression over several lines when it is clearer to do so. eva evaluates what you enter; it does not require a calculator function or an __info() function.

4. Editor features

Python syntax highlighting distinguishes code elements visually.
Line numbers make it easier to locate an error reported by a syntax check.
Bracket matching highlights the matching parenthesis, square bracket, or brace near the cursor.
Auto-close brackets and quotes adds the matching ), ], }, single quote, or double quote after you type an opening character. Type a closing character to move past an existing match. Press Backspace between an empty matching pair to remove both characters.
Four-space indentation is used for Tab, which matches normal Python style.
Multiline indentation applies Tab or Shift+Tab to every selected line.
Column-100 ruler provides a subtle vertical guide for keeping lines readable.
Line wrapping keeps long lines visible without requiring horizontal scrolling.
Browser context menu remains available for familiar commands such as Copy, Paste, and Select All.

5. Keyboard shortcuts

Key	Action
`Tab`	Insert four spaces at the cursor, or indent all selected lines.
`Shift+Tab`	Outdent the current line, or outdent all selected lines.
`Ctrl+S` (Windows/Linux)	Download the current editor contents as a Python file.
`Cmd+S` (macOS)	Download the current editor contents as a Python file.
`F11`	Toggle fullscreen editing for the current code editor.

6. File and fullscreen controls

The buttons below the editor let you move code between qCalc and a local file:

Use the Upload from Python file button to load a .py file into the editor.
Use the Save to Python file button, or the Ctrl+S/Cmd+S shortcut, to download the current contents as a .py file.
Use the small fullscreen control at the editor corner, or F11, to make the editor fill the screen. Use the same control or F11 again to return to the normal view.

After changing code in mycal, run qCalc's syntax check and validation before saving the calculator.

Code Editor