1 files changed, 38 insertions, 0 deletions
diff --git a/src/background/shared/zooms.js b/src/background/shared/zooms.js
new file mode 100644
index 0000000..e3e2aa6
--- /dev/null
+++ b/src/background/shared/zooms.js
@@ -0,0 +1,38 @@
+// For chromium
+// const ZOOM_SETTINGS = [
+//   0.25, 0.33, 0.50, 0.66, 0.75, 0.80, 0.90, 1.00,
+//   1.10, 1.25, 1.50, 1.75, 2.00, 2.50, 3.00, 4.00, 5.00
+// ];
+
+const ZOOM_SETTINGS = [
+  0.33, 0.50, 0.66, 0.75, 0.80, 0.90, 1.00,
+  1.10, 1.25, 1.50, 1.75, 2.00, 2.50, 3.00
+];
+
+const zoomIn = (tabId = undefined) => {
+  return browser.tabs.getZoom(tabId).then((factor) => {
+    for (let f of ZOOM_SETTINGS) {
+      if (f > factor) {
+        browser.tabs.setZoom(tabId, f);
+        break;
+      }
+    }
+  });
+};
+
+const zoomOut = (tabId = undefined) => {
+  return browser.tabs.getZoom(tabId).then((factor) => {
+    for (let f of [].concat(ZOOM_SETTINGS).reverse()) {
+      if (f < factor) {
+        browser.tabs.setZoom(tabId, f);
+        break;
+      }
+    }
+  });
+};
+
+const neutral = (tabId = undefined) => {
+  return browser.tabs.setZoom(tabId, 1);
+};
+
+export { zoomIn, zoomOut, neutral };