Create functions for the cases of isMouseButton

jshint was showing a warning that there was no break statement
after the first case, which there doesn't need to be.

The most straightforward way to fix this without using the unclear
// jshint ignore:line
is to just have two functions.

This change also updates invocations of isMouseButton to use
the exact case function, as this will remove the need to check
the case of mosueEvent.type. This was done because onMouseMove
is invoked at a high frequency.

2 files changed, 28 insertions, 16 deletions

diff --git a/ext/fg/js/frontend.js b/ext/fg/js/frontend.js
index e67008df..7c62b51b 100644
--- a/ext/fg/js/frontend.js
+++ b/ext/fg/js/frontend.js
@@ -80,7 +80,7 @@ class Frontend {
     onMouseMove(e) {
         this.popupTimerClear();
 
-        if (this.pendingLookup || Frontend.isMouseButton('primary', e)) {
+        if (this.pendingLookup || Frontend.isMouseButtonDown('primary', e)) {
             return;
         }
 
@@ -88,7 +88,7 @@ class Frontend {
         const scanningModifier = scanningOptions.modifier;
         if (!(
             Frontend.isScanningModifierPressed(scanningModifier, e) ||
-            (scanningOptions.middleMouse && Frontend.isMouseButton('auxiliary', e))
+            (scanningOptions.middleMouse && Frontend.isMouseButtonDown('auxiliary', e))
         )) {
             return;
         }
@@ -504,18 +504,30 @@ class Frontend {
         switch (mouseEvent.type) {
             case 'mouseup':
             case 'mousedown':
-            case 'click': switch (button) {
-                case 'primary': return mouseEvent.button === 0;
-                case 'secondary': return mouseEvent.button === 2;
-                case 'auxiliary': return mouseEvent.button === 1;
-                default: return false;
-            }
-            default: switch (button) {
-                case 'primary': return (mouseEvent.buttons & 0x1) !== 0x0;
-                case 'secondary': return (mouseEvent.buttons & 0x2) !== 0x0;
-                case 'auxiliary': return (mouseEvent.buttons & 0x4) !== 0x0;
-                default: return false;
-            }
+            case 'click':
+                return Frontend.isMouseButtonPressed(button, mouseEvent);
+            default:
+                return Frontend.isMouseButtonDown(button, mouseEvent);
+        }
+    }
+
+    static isMouseButtonPressed(button, mouseEvent) {
+        const mouseEventButton = mouseEvent.button;
+        switch (button) {
+            case 'primary': return mouseEventButton === 0;
+            case 'secondary': return mouseEventButton === 2;
+            case 'auxiliary': return mouseEventButton === 1;
+            default: return false;
+        }
+    }
+
+    static isMouseButtonDown(button, mouseEvent) {
+        const mouseEventButtons = mouseEvent.buttons;
+        switch (button) {
+            case 'primary': return (mouseEventButtons & 0x1) !== 0x0;
+            case 'secondary': return (mouseEventButtons & 0x2) !== 0x0;
+            case 'auxiliary': return (mouseEventButtons & 0x4) !== 0x0;
+            default: return false;
         }
     }
 }
diff --git a/ext/mixed/js/display.js b/ext/mixed/js/display.js
index 5a824561..801011df 100644
--- a/ext/mixed/js/display.js
+++ b/ext/mixed/js/display.js
@@ -83,7 +83,7 @@ class Display {
     }
 
     onGlossaryMouseDown(e) {
-        if (Frontend.isMouseButton('primary', e)) {
+        if (Frontend.isMouseButtonPressed('primary', e)) {
             this.clickScanPrevent = false;
         }
     }
@@ -93,7 +93,7 @@ class Display {
     }
 
     onGlossaryMouseUp(e) {
-        if (!this.clickScanPrevent && Frontend.isMouseButton('primary', e)) {
+        if (!this.clickScanPrevent && Frontend.isMouseButtonPressed('primary', e)) {
             this.onTermLookup(e);
         }
     }