3 files changed, 43 insertions, 0 deletions
diff --git a/src/background/index.js b/src/background/index.js
index f3bd65a..cfd5e77 100644
--- a/src/background/index.js
+++ b/src/background/index.js
@@ -1,6 +1,7 @@
 import * as actions from '../shared/actions';
 import * as tabs from './tabs';
 import * as commands from './commands';
+import * as zooms from './zooms';
 import KeyQueue from './key-queue';
 
 const queue = new KeyQueue();
@@ -38,6 +39,12 @@ const doBackgroundAction = (sender, action) => {
   case actions.TABS_NEXT:
     tabs.selectNextTab(sender.tab.index, actions[1] || 1);
     break;
+  case actions.ZOOM_IN:
+    zooms.zoomIn();
+    break;
+  case actions.ZOOM_OUT:
+    zooms.zoomOut();
+    break;
   }
 }
 
diff --git a/src/background/key-queue.js b/src/background/key-queue.js
index a07c7f4..6319431 100644
--- a/src/background/key-queue.js
+++ b/src/background/key-queue.js
@@ -13,6 +13,8 @@ const DEFAULT_KEYMAP = [
   { keys: [{ code: KeyboardEvent.DOM_VK_U }], action: [ actions.TABS_REOPEN]},
   { keys: [{ code: KeyboardEvent.DOM_VK_H }], action: [ actions.TABS_PREV, 1 ]},
   { keys: [{ code: KeyboardEvent.DOM_VK_L }], action: [ actions.TABS_NEXT, 1 ]},
+  { keys: [{ code: KeyboardEvent.DOM_VK_Z }, { code: KeyboardEvent.DOM_VK_I }], action: [ actions.ZOOM_IN ]},
+  { keys: [{ code: KeyboardEvent.DOM_VK_Z }, { code: KeyboardEvent.DOM_VK_O }], action: [ actions.ZOOM_OUT ]},
   { keys: [{ code: KeyboardEvent.DOM_VK_F }], action: [ actions.FOLLOW_START, false ]},
   { keys: [{ code: KeyboardEvent.DOM_VK_F, shift: true }], action: [ actions.FOLLOW_START, true ]},
   { keys: [{ code: KeyboardEvent.DOM_VK_H, shift: true }], action: [ actions.HISTORY_PREV ]},
diff --git a/src/background/zooms.js b/src/background/zooms.js
new file mode 100644
index 0000000..def2878
--- /dev/null
+++ b/src/background/zooms.js
@@ -0,0 +1,34 @@
+// 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) => {
+  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) => {
+  browser.tabs.getZoom(tabId).then((factor) => {
+    for (let f of [].concat(ZOOM_SETTINGS).reverse()) {
+      if (f < factor) {
+        browser.tabs.setZoom(tabId, f);
+        break;
+      }
+    }
+  });
+}
+
+export { zoomIn, zoomOut };