split cli and helper, add bin entry to package.json

swm.js

@@ -0,0 +1,90 @@
+'use strict';
+
+const xrandrParse = require('xrandr-parse');
+const exec = require('child_process').exec;
+
+function getDevices() {
+    return new Promise((resolve, reject) => {
+        exec('xrandr', (err, stdout, stderr) => {
+            if (err || stderr) {
+                reject(err);
+                return;
+            }
+            resolve(xrandrParse(stdout));
+        });
+    });
+}
+
+function generateXrandrOptions(monitorList, devices) {
+    let xrandrOptions = '';
+    let deviceOrder = Object.keys(devices).sort();
+
+    // remove explicitly selected monitors inside the array and add them to the
+    // beginning in the order they have been specified.
+    monitorList.reverse().forEach((monitor) => {
+        const index = deviceOrder.indexOf(monitor);
+        if (index < 0) {
+            console.error('Unkown monitor', monitor, '(ignored)');
+            return;
+        }
+        deviceOrder.splice(index, 1);
+        deviceOrder.unshift(monitor);
+    });
+
+    let prevDevice;
+    deviceOrder.forEach(deviceKey => {
+        const device = devices[deviceKey];
+
+        const deviceStatus = device.connected ? '--auto' : '--off';
+        const monitorOptions = ['', '--output', deviceKey, deviceStatus];
+
+        if (device.connected) {
+            if (prevDevice) {
+                monitorOptions.push(['--right-of', prevDevice].join(' '));
+            }
+
+            prevDevice = deviceKey;
+        }
+        xrandrOptions += monitorOptions.join(' ');
+    });
+
+    // sanity check if at least one monitor is on
+    if (xrandrOptions.indexOf('--auto') === -1) {
+        throw 'Non of the given monitors are connected, aborting...';
+    }
+
+    return xrandrOptions;
+}
+
+function switchDevices(xrandrOptions) {
+    return new Promise((resolve, reject) => {
+        const cmd = 'xrandr ' + xrandrOptions;
+        exec(cmd, (err, stdout, stderr) => {
+            if (err || stderr) {
+                reject(err);
+                return;
+            }
+            resolve();
+        });
+    });
+}
+
+function executePostCmd(postCmd) {
+    if (!postCmd) {
+        return;
+    }
+    return new Promise((resolve, reject) => {
+        exec(postCmd, (err, stdout, stderr) => {
+            if (err || stderr) {
+                reject(err);
+                return;
+            }
+            resolve();
+        });
+    });
+}
+
+module.exports.getDevices = getDevices;
+module.exports.generateXrandrOptions = generateXrandrOptions;
+module.exports.switchDevices = switchDevices;
+module.exports.executePostCmd = executePostCmd;