From b6eb33f2057fb185ad608ef988aec78e2a8dd572 Mon Sep 17 00:00:00 2001
From: Grzegorz Kucmierz <gkucmierz@gmail.com>
Date: Wed, 4 Mar 2026 04:11:05 +0000
Subject: [PATCH] feat(qr): refine gradient drag handles with visual offsets,
 magnetic snapping to corners, and floating icon toggle

---
 src/components/tools/QrCode.vue | 118 ++++++++++++++++++++++++++------
 1 file changed, 98 insertions(+), 20 deletions(-)

diff --git a/src/components/tools/QrCode.vue b/src/components/tools/QrCode.vue
index 56019d1..a95bbbd 100644
--- a/src/components/tools/QrCode.vue
+++ b/src/components/tools/QrCode.vue
@@ -1,6 +1,6 @@
 <script setup>
-import { ref, watch, onMounted } from 'vue'
-import { Download } from 'lucide-vue-next'
+import { ref, watch, onMounted, computed, onUnmounted } from 'vue'
+import { Download, Eye, EyeOff } from 'lucide-vue-next'
 import QRCode from 'qrcode'
 import { useFillHeight } from '../../composables/useFillHeight'
 import { useLocalStorage } from '../../composables/useLocalStorage'
@@ -23,11 +23,49 @@ const fgColor1 = useLocalStorage('fgColor1', '#000000', 'qr-code')
 const fgColor2 = useLocalStorage('fgColor2', '#10b981', 'qr-code')
 const fgGradPos = useLocalStorage('fgGradPos', { x1: 0, y1: 0, x2: 100, y2: 100 }, 'qr-code')
 const showHandles = useLocalStorage('showHandles', true, 'qr-code')
+const format = useLocalStorage('format', 'png', 'qr-code')
 
 const svgContent = ref('')
 const previewRef = ref(null)
 const qrFrameRef = ref(null)
 
+const fgLinePts = computed(() => getLineEndPoints(fgGradPos.value))
+const bgLinePts = computed(() => getLineEndPoints(bgGradPos.value))
+
+const getLineEndPoints = (pos) => {
+  if (!qrFrameRef.value) return { x1: pos.x1, y1: pos.y1, x2: pos.x2, y2: pos.y2 }
+  const rect = qrFrameRef.value.getBoundingClientRect()
+  if (rect.width === 0 || rect.height === 0) return { x1: pos.x1, y1: pos.y1, x2: pos.x2, y2: pos.y2 }
+
+  // Handle radius in pixels (14/2 = 7px) plus half the line stroke width (1/2 = 0.5px) if needed
+  const VISUAL_OFFSET_PX = 1;
+  const rPx = 7 - VISUAL_OFFSET_PX;
+
+  const dx = (pos.x2 - pos.x1) * rect.width / 100
+  const dy = (pos.y2 - pos.y1) * rect.height / 100
+  const distPx = Math.sqrt(dx * dx + dy * dy)
+
+  if (distPx <= rPx * 2) {
+    // Too close, don't show line
+    return { x1: pos.x1, y1: pos.y1, x2: pos.x1, y2: pos.y1 }
+  }
+
+  const angle = Math.atan2(dy, dx)
+
+  // Calculate offsets in percentages (using radius, not diameter)
+  // adding extra 1px to accommodate the stroke/shadow
+  const effectiveRPx = rPx + 1
+  const xOffsetPct = (Math.cos(angle) * effectiveRPx / rect.width) * 100
+  const yOffsetPct = (Math.sin(angle) * effectiveRPx / rect.height) * 100
+
+  return {
+    x1: pos.x1 + xOffsetPct,
+    y1: pos.y1 + yOffsetPct,
+    x2: pos.x2 - xOffsetPct,
+    y2: pos.y2 - yOffsetPct
+  }
+}
+
 const activeHandle = ref(null)
 
 const startDrag = (e, handleStr) => {
@@ -52,6 +90,23 @@ const onDrag = (e) => {
   x = Math.max(0, Math.min(100, x))
   y = Math.max(0, Math.min(100, y))
 
+  // Snap to 5 points (Corners + Center)
+  // Distance threshold in percentages, roughly matching handle diameter mapping
+  const snapDist = 5
+  const snapPoints = [
+    { x: 0, y: 0 }, { x: 100, y: 0 },
+    { x: 0, y: 100 }, { x: 100, y: 100 },
+    { x: 50, y: 50 }
+  ]
+
+  for (const pt of snapPoints) {
+    if (Math.abs(x - pt.x) < snapDist && Math.abs(y - pt.y) < snapDist) {
+      x = pt.x
+      y = pt.y
+      break
+    }
+  }
+
   const [type, point] = activeHandle.value.split(':')
   const posRef = type === 'fg' ? fgGradPos : bgGradPos
   posRef.value[`x${point}`] = Math.round(x)
@@ -141,8 +196,6 @@ onMounted(() => {
   if (text.value) generateQR()
 })
 
-import { onUnmounted } from 'vue'
-
 onUnmounted(() => {
   if (worker) {
     worker.terminate()
@@ -285,29 +338,35 @@ const triggerDownload = (blob, filename) => {
                 <template v-if="showHandles">
                   <!-- Background Gradient Handles -->
                   <template v-if="!isBgTransparent && bgType !== 'solid'">
-                    <svg class="grad-line-svg"><line :x1="bgGradPos.x1 + '%'" :y1="bgGradPos.y1 + '%'" :x2="bgGradPos.x2 + '%'" :y2="bgGradPos.y2 + '%'" class="bg-line" /></svg>
                     <div class="grad-handle bg-handle handle-1" :style="{ left: bgGradPos.x1 + '%', top: bgGradPos.y1 + '%' }" @mousedown="startDrag($event, 'bg:1')" @touchstart.prevent="startDrag($event, 'bg:1')"></div>
                     <div class="grad-handle bg-handle handle-2" :style="{ left: bgGradPos.x2 + '%', top: bgGradPos.y2 + '%' }" @mousedown="startDrag($event, 'bg:2')" @touchstart.prevent="startDrag($event, 'bg:2')"></div>
+                    <svg class="grad-line-svg"><line :x1="bgLinePts.x1 + '%'" :y1="bgLinePts.y1 + '%'" :x2="bgLinePts.x2 + '%'" :y2="bgLinePts.y2 + '%'" class="bg-line" /></svg>
                   </template>
 
                   <!-- Foreground Gradient Handles -->
                   <template v-if="fgType !== 'solid'">
-                    <svg class="grad-line-svg"><line :x1="fgGradPos.x1 + '%'" :y1="fgGradPos.y1 + '%'" :x2="fgGradPos.x2 + '%'" :y2="fgGradPos.y2 + '%'" class="fg-line" /></svg>
                     <div class="grad-handle fg-handle handle-1" :style="{ left: fgGradPos.x1 + '%', top: fgGradPos.y1 + '%' }" @mousedown="startDrag($event, 'fg:1')" @touchstart.prevent="startDrag($event, 'fg:1')"></div>
                     <div class="grad-handle fg-handle handle-2" :style="{ left: fgGradPos.x2 + '%', top: fgGradPos.y2 + '%' }" @mousedown="startDrag($event, 'fg:2')" @touchstart.prevent="startDrag($event, 'fg:2')"></div>
+                    <svg class="grad-line-svg"><line :x1="fgLinePts.x1 + '%'" :y1="fgLinePts.y1 + '%'" :x2="fgLinePts.x2 + '%'" :y2="fgLinePts.y2 + '%'" class="fg-line" /></svg>
                   </template>
                 </template>
              </div>
           </div>
+
+           <!-- Overlay Icon Toggle -->
+           <button
+              v-if="fgType !== 'solid' || (!isBgTransparent && bgType !== 'solid')"
+              class="icon-btn edit-toggle-btn"
+              :class="{ 'active': showHandles }"
+              @click="showHandles = !showHandles"
+              title="Toggle edit handles"
+            >
+              <Eye v-if="showHandles" size="20" />
+              <EyeOff v-else size="20" />
+           </button>
         </div>
 
         <div class="download-settings">
-          <div class="control-group" v-if="fgType !== 'solid' || (!isBgTransparent && bgType !== 'solid')">
-            <label class="checkbox-label">
-              <input type="checkbox" v-model="showHandles"> Show edit handles
-            </label>
-          </div>
-
           <div class="control-group">
             <label>Size (px)</label>
             <div class="number-control size-control">
@@ -442,6 +501,28 @@ const triggerDownload = (blob, filename) => {
   width: 100%;
   min-height: 0;
   container-type: size;
+  position: relative;
+}
+
+.edit-toggle-btn {
+  position: absolute;
+  top: 0;
+  right: 0;
+  z-index: 20;
+  color: var(--text-secondary);
+  opacity: 0.6;
+  background: var(--panel-bg);
+  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
+}
+
+.edit-toggle-btn:hover {
+  opacity: 1;
+  color: var(--text-strong);
+}
+
+.edit-toggle-btn.active {
+  color: var(--primary-accent);
+  opacity: 0.9;
 }
 
 :root[data-theme="light"] .preview-section {
@@ -486,7 +567,7 @@ const triggerDownload = (blob, filename) => {
   width: 100%;
   height: 100%;
   pointer-events: none;
-  z-index: 5;
+  z-index: 15;
 }
 
 .grad-handle {
@@ -498,21 +579,18 @@ const triggerDownload = (blob, filename) => {
   cursor: grab;
   z-index: 10;
   touch-action: none;
-  background: rgba(0, 0, 0, 0.5);
-  box-shadow: 0 0 3px 1px rgba(255, 255, 255, 0.9);
+  background: rgb(255, 255, 255);
+  box-shadow: 0 0 4px 0px rgb(0, 0, 0);
 }
 
 .grad-handle:active {
   cursor: grabbing;
 }
 
-.fg-handle { }
-.bg-handle { }
-
 .fg-line, .bg-line {
-  stroke: rgba(0, 0, 0, 0.5);
+  stroke: rgb(255, 255, 255);
   stroke-width: 1;
-  filter: drop-shadow(0px 0px 2px rgba(255,255,255,0.9));
+  filter: drop-shadow(0px 0px 2px rgb(0, 0, 0));
 }
 
 .download-settings {