INNER CODE UNIT · JavaScript

heightPercentageToDP

marudy/react-native-responsive-screen · index.js:31

const heightPercentageToDP = heightPercent => {
  // Parse string percentage input and convert it to number.
  const elemHeight = typeof heightPercent === "number" ? heightPercent : parseFloat(heightPercent);

  // Use PixelRatio.roundToNearestPixel method in order to round the layout
  // size (dp) to the nearest one that correspons to an integer number of pixels.
  return PixelRatio.roundToNearestPixel(screenHeight * elemHeight / 100);
};

/**
 * Event listener function that detects orientation change (every time it occurs) and triggers 
 * screen rerendering. It does that, by changing the state of the screen where the function is
 * called. State changing occurs for a new state variable with the name 'orientation' that will
 * always hold the current value of the orientation after the 1st orientation change.
 * Invoke it inside the screen's constructor or in componentDidMount lifecycle method.
 * @param {object} that Screen's class component this variable. The function needs it to
 *                      invoke setState method and trigger screen rerender (this.setState()).
 */

View source record →

📰 Research Paper
Loading…
⏳ Fetching content…