Updated isModelEmptyFast to consider changed indentation as not empty…

… string (#2625)

* Updated isModelEmptyFast

* Tests fix

packages/roosterjs-content-model-plugins/lib/watermark/isModelEmptyFast.ts

@@ -25,6 +25,11 @@ export function isModelEmptyFast(model: ContentModelDocument): boolean {
         )
     ) {
         return false; // Has meaningful segments, it is not empty
+    } else if (
+        (firstBlock.format.marginRight && parseFloat(firstBlock.format.marginRight) > 0) ||
+        (firstBlock.format.marginLeft && parseFloat(firstBlock.format.marginLeft) > 0)
+    ) {
+        return false; // Has margin (indentation is changed), it is not empty
     } else {
         return firstBlock.segments.filter(x => x.segmentType == 'Br').length <= 1; // If there are more than one BR, it is not empty, otherwise it is empty
     }

packages/roosterjs-content-model-plugins/test/watermark/isModelEmptyFastTest.ts

@@ -99,6 +99,32 @@ describe('isModelEmptyFast', () => {
         expect(result).toBeTrue();
     });
 
+    it('Single Paragraph block - right margin 10px', () => {
+        const model = createContentModelDocument();
+        const para = createParagraph();
+        para.format.marginRight = '10px';
+
+        para.segments.push(createBr());
+        model.blocks.push(para);
+
+        const result = isModelEmptyFast(model);
+
+        expect(result).toBeFalse();
+    });
+
+    it('Single Paragraph block - left margin 0.25rem', () => {
+        const model = createContentModelDocument();
+        const para = createParagraph();
+        para.format.marginLeft = '0.25rem';
+
+        para.segments.push(createBr());
+        model.blocks.push(para);
+
+        const result = isModelEmptyFast(model);
+
+        expect(result).toBeFalse();
+    });
+
     it('Single Paragraph block - two BR segment', () => {
         const model = createContentModelDocument();
         const para = createParagraph();