Dynamic Reposition.sketchplugin

// Reposition all content to still have the same margin after the background is resized (cmd p)


// Change to use another default name;
var bgName = 'background';

var background;
var contentLayers = [];


// Puts all layers and groups except the background in an array.
function getContent() {
	var group = selection[0].layers();

	for( var i=0; i<[group count]; i++) {

		if(group.array()[i].name() != bgName) {
			contentLayers.push(group.array()[i]);
		}
	}
}

// fetches the positions and repostions the groups and layers.
function positionContent() {
	var bgX = background.frame().x();
	var bgY = background.frame().y();
	var bgW = background.frame().width();
	var bgH = background.frame().height();

	var margin = [];


	// Position all layers
	for( var i=0; i<contentLayers.length; i++ ) {
		var currentLayer = contentLayers[i];
		var margin = getMargins([currentLayer name]);

		var top = null;
		var right = null;
		var bottom = null;
		var left = null;
		var width = null;
		var height = null;
		var fontSize = null;

		// get format offset
		for( var j=0; j<margin.length; j+=2 ) {

			switch(margin[j].toLowerCase()) {
				case 't':
				case 'top':
					top = Number(margin[j+1]);
					break;

				case 'r':
				case 'right':
					right = Number(margin[j+1]);
					break;

				case 'b':
				case 'bottom':
					bottom = Number(margin[j+1]);
					break;

				case 'l':
				case 'left':
					left = Number(margin[j+1]);
					break;

				case 'w':
				case 'width':
					width = Number(margin[j+1]);
					break;

				case 'h':
				case 'height':
					height = Number(margin[j+1]);
					break;

				case 'fs':
				case 'fontSize':
					fontSize = Number(margin[j+1]);
					break;
			}
		}

		//check if font and has a size set
		if (currentLayer.className() == "MSTextLayer" && fontSize != null){
			currentLayer.setFontSize(fontSize);
			currentLayer.frame().height = currentLayer.lineSpacing();
		}

		// set new width
		if( right != null && left != null && width != null ) currentLayer.frame().width = bgW - (left + right);

		// set new height
		if( top != null && bottom != null && height != null ) currentLayer.frame().height = bgH - (top + bottom);

		// resize layer if size is set
		if( width  != null )currentLayer.frame().width = width;
		if( height != null) currentLayer.frame().height = height;

		var currW = [currentLayer frame].width());
		var currH = [currentLayer frame].height();

		// position layer
		if( bottom != null ) currentLayer.frame().y = (bgY + bgH) - (bottom + currH);
		if( top    != null ) currentLayer.frame().y = bgY + top;
		if( right  != null ) currentLayer.frame().x = (bgX + bgW) - (right + currW);
		if( left   != null ) currentLayer.frame().x = bgX + left;

		// align middle
		if( top == null && bottom == null ) currentLayer.frame().y = (bgY + bgH)*.5 - currH*.5;
		// align center
		if( right == null && left == null ) currentLayer.frame().x = ((bgX + bgW)*.5) - (currW*.5);

	}
	[doc showMessage:"The content has been repositioned."]
}

function getMargins(name) {
	var possibleDividers = [' t:',' top:',' r:',' right:',' b:',' bottom:',' l:',' left:', ' width:', ' w:', ' fontSize:', ' fs:'];
	var index = 0;

	for(var i=0; i<possibleDividers.length; i++) {

		if(name.toLowerCase().indexOf(possibleDividers[i]) != -1) {
			index = name.indexOf(possibleDividers[i]);
			break;
		}
	}

	var margins = name.slice(index).replace(/\s+/g, '');
	return margins.split(":");
}


function findBackgroundByName(){
	var group = selection[0].layers();

	for( var i=0; i<[group count]; i++) {

		if(group.array()[i].name() == bgName) {
			return group.array()[i];
		}
	}
}

function findBackgroundBySize(){
	var group = selection[0].layers();
	var maxWidth = 0;
	var maxHeight = 0;
	var tempBG;

	for( var i=0; i<[group count]; i++) {
		var w = group.array()[i].frame().width();
		var h = group.array()[i].frame().height();

		if( w > maxWidth && h > maxHeight ){
			maxWidth = w;
			maxHeight = h;
			tempBG = group.array()[i];
		}
	}
	return tempBG;
}


// Needs to have a group selected to start the script.
if( [selection count] > 0 ){
	background = findBackgroundByName();
	if( background == null ) { background = findBackgroundBySize();	}

	getContent();
	positionContent();
} else {
	alert("Nothing selected","Please select a group");
}

function alert(title, text) {
	var app = [NSApplication sharedApplication];
	[app displayDialog:text withTitle:title]
}