lvtinydom: createXPointer(): better handle <br/> edge cases

poire-z · poire-z · commit 2db70cd4f6b5 · 2024-11-23T22:54:26.000+01:00
Fix text selection when starting/ending selection on
a blank line created by &lt;br/&gt;&lt;br/&gt; (which would just not
work) or at the end of a paragraph ending with &lt;br/&gt;
(which would select the full paragraph).
diff --git a/crengine/src/lvtinydom.cpp b/crengine/src/lvtinydom.cpp
@@ -9759,10 +9759,16 @@ ldomXPointer ldomDocument::createXPointer( lvPoint pt, int direction, bool stric
                 return ldomXPointer(node, 0);
             }
             // It is a word
-            if ( find_first ) // return xpointer to logical start of word
+            if ( find_first ) { // return xpointer to logical start of word
+                if ( node->isElement() ) // (see comment about <br/><br/> below)
+                    return ldomXPointer(node, 0);
                 return ldomXPointer( node, src->t.offset + word->t.start );
-            else // return xpointer to logical end of word
+            }
+            else { // return xpointer to logical end of word
+                if ( node->isElement() )
+                    return ldomXPointer(node, 0);
                 return ldomXPointer( node, src->t.offset + word->t.start + word->t.len );
+            }
         }
 
         // Found line, searching for word (words are in visual order)
@@ -9841,24 +9847,36 @@ ldomXPointer ldomDocument::createXPointer( lvPoint pt, int direction, bool stric
                 font->measureText( str.c_str()+word->t.start, word->t.len, width, flg, word->width+50, '?',
                             src->lang_cfg, src->letter_spacing + word->added_letter_spacing, false, hints);
 
+                // In some special cases, node may be an element and not a text node (ie. on a blank
+                // line caused by <br/><br/> where our word is a space generated by lvrend): below,
+                // we must return node with an offset of 0 (to avoid getting xpointer like p[2]/br[3].1
+                // which may fail being resolved back to the br node).
                 bool word_is_rtl = word->flags & LTEXT_WORD_DIRECTION_IS_RTL;
                 if ( word_is_rtl ) {
                     for ( int i=word->t.len-1; i>=0; i-- ) {
                         int xx = ( i>0 ) ? (width[i-1] + width[i])/2 : width[i]/2;
                         xx = word->width - xx;
                         if ( x < word->x + xx ) {
+                            if ( node->isElement() )
+                                return ldomXPointer(node, 0);
                             return ldomXPointer( node, src->t.offset + word->t.start + i );
                         }
                     }
+                    if ( node->isElement() )
+                        return ldomXPointer(node, 0);
                     return ldomXPointer( node, src->t.offset + word->t.start );
                 }
                 else {
                     for ( int i=0; i<word->t.len; i++ ) {
                         int xx = ( i>0 ) ? (width[i-1] + width[i])/2 : width[i]/2;
                         if ( x < word->x + xx ) {
+                            if ( node->isElement() )
+                                return ldomXPointer(node, 0);
                             return ldomXPointer( node, src->t.offset + word->t.start + i );
                         }
                     }
+                    if ( node->isElement() )
+                        return ldomXPointer( node, 0 );
                     return ldomXPointer( node, src->t.offset + word->t.start + word->t.len );
                 }
             }
@@ -10456,6 +10474,16 @@ bool ldomXPointer::getRect(lvRect & rect, bool extended, bool adjusted) const
                     }
                 }
             }
+            if ( frmline->word_count == 0 && l == txtform->GetLineCount() - 1 && frmline->height == 0 ) {
+                // Handle a special case: we may end up setting the last added line a height of
+                // zero when we realize no word would be added. We don't want to return the full
+                // final node.
+                rect.left = rc.left;
+                rect.top = rc.top + frmline->y;
+                rect.right = rect.left + 1; // not the right word: no char width
+                rect.bottom = rect.top + frmline->height + 1;
+                return true;
+            }
         }
         // return false;
         // Not found, which is possible with a final node with only empty

Original file line number	Diff line number	Diff line change
`@@ -9759,10 +9759,16 @@ ldomXPointer ldomDocument::createXPointer( lvPoint pt, int direction, bool stric`
`9759`	`9759`	`return ldomXPointer(node, 0);`
`9760`	`9760`	`}`
`9761`	`9761`	`// It is a word`
`9762`		`- if ( find_first ) // return xpointer to logical start of word`
	`9762`	`+ if ( find_first ) { // return xpointer to logical start of word`
	`9763`	`+ if ( node->isElement() ) // (see comment about <br/><br/> below)`
	`9764`	`+ return ldomXPointer(node, 0);`
`9763`	`9765`	`return ldomXPointer( node, src->t.offset + word->t.start );`
`9764`		`- else // return xpointer to logical end of word`
	`9766`	`+ }`
	`9767`	`+ else { // return xpointer to logical end of word`
	`9768`	`+ if ( node->isElement() )`
	`9769`	`+ return ldomXPointer(node, 0);`
`9765`	`9770`	`return ldomXPointer( node, src->t.offset + word->t.start + word->t.len );`
	`9771`	`+ }`
`9766`	`9772`	`}`
`9767`	`9773`
`9768`	`9774`	`// Found line, searching for word (words are in visual order)`
`@@ -9841,24 +9847,36 @@ ldomXPointer ldomDocument::createXPointer( lvPoint pt, int direction, bool stric`
`9841`	`9847`	`font->measureText( str.c_str()+word->t.start, word->t.len, width, flg, word->width+50, '?',`
`9842`	`9848`	`src->lang_cfg, src->letter_spacing + word->added_letter_spacing, false, hints);`
`9843`	`9849`
	`9850`	`+ // In some special cases, node may be an element and not a text node (ie. on a blank`
	`9851`	`+ // line caused by <br/><br/> where our word is a space generated by lvrend): below,`
	`9852`	`+ // we must return node with an offset of 0 (to avoid getting xpointer like p[2]/br[3].1`
	`9853`	`+ // which may fail being resolved back to the br node).`
`9844`	`9854`	`bool word_is_rtl = word->flags & LTEXT_WORD_DIRECTION_IS_RTL;`
`9845`	`9855`	`if ( word_is_rtl ) {`
`9846`	`9856`	`for ( int i=word->t.len-1; i>=0; i-- ) {`
`9847`	`9857`	`int xx = ( i>0 ) ? (width[i-1] + width[i])/2 : width[i]/2;`
`9848`	`9858`	`xx = word->width - xx;`
`9849`	`9859`	`if ( x < word->x + xx ) {`
	`9860`	`+ if ( node->isElement() )`
	`9861`	`+ return ldomXPointer(node, 0);`
`9850`	`9862`	`return ldomXPointer( node, src->t.offset + word->t.start + i );`
`9851`	`9863`	`}`
`9852`	`9864`	`}`
	`9865`	`+ if ( node->isElement() )`
	`9866`	`+ return ldomXPointer(node, 0);`
`9853`	`9867`	`return ldomXPointer( node, src->t.offset + word->t.start );`
`9854`	`9868`	`}`
`9855`	`9869`	`else {`
`9856`	`9870`	`for ( int i=0; i<word->t.len; i++ ) {`
`9857`	`9871`	`int xx = ( i>0 ) ? (width[i-1] + width[i])/2 : width[i]/2;`
`9858`	`9872`	`if ( x < word->x + xx ) {`
	`9873`	`+ if ( node->isElement() )`
	`9874`	`+ return ldomXPointer(node, 0);`
`9859`	`9875`	`return ldomXPointer( node, src->t.offset + word->t.start + i );`
`9860`	`9876`	`}`
`9861`	`9877`	`}`
	`9878`	`+ if ( node->isElement() )`
	`9879`	`+ return ldomXPointer( node, 0 );`
`9862`	`9880`	`return ldomXPointer( node, src->t.offset + word->t.start + word->t.len );`
`9863`	`9881`	`}`
`9864`	`9882`	`}`
`@@ -10456,6 +10474,16 @@ bool ldomXPointer::getRect(lvRect & rect, bool extended, bool adjusted) const`
`10456`	`10474`	`}`
`10457`	`10475`	`}`
`10458`	`10476`	`}`
	`10477`	`+ if ( frmline->word_count == 0 && l == txtform->GetLineCount() - 1 && frmline->height == 0 ) {`
	`10478`	`+ // Handle a special case: we may end up setting the last added line a height of`
	`10479`	`+ // zero when we realize no word would be added. We don't want to return the full`
	`10480`	`+ // final node.`
	`10481`	`+ rect.left = rc.left;`
	`10482`	`+ rect.top = rc.top + frmline->y;`
	`10483`	`+ rect.right = rect.left + 1; // not the right word: no char width`
	`10484`	`+ rect.bottom = rect.top + frmline->height + 1;`
	`10485`	`+ return true;`
	`10486`	`+ }`
`10459`	`10487`	`}`
`10460`	`10488`	`// return false;`
`10461`	`10489`	`// Not found, which is possible with a final node with only empty`