DocumentWidget: Advanced text selection

Double click to select by word, triple click by paragraph.

IssueID #134

4 files changed, 124 insertions, 24 deletions

diff --git a/src/ui/documentwidget.c b/src/ui/documentwidget.c
index b3508b8d..6bb16a93 100644
--- a/src/ui/documentwidget.c
+++ b/src/ui/documentwidget.c
@@ -198,6 +198,7 @@ struct Impl_DocumentWidget {
     iString *      certSubject;
     int            redirectCount;
     iRangecc       selectMark;
+    iRangecc       initialSelectMark; /* for word/line selection */
     iRangecc       foundMark;
     int            pageMargin;
     iPtrArray      visibleLinks;
@@ -2325,6 +2326,15 @@ static iChar linkOrdinalChar_DocumentWidget_(const iDocumentWidget *d, size_t or
     return 0;
 }
 
+static void beginMarkingSelection_DocumentWidget_(iDocumentWidget *d, iInt2 pos) {
+    setFocus_Widget(NULL); /* TODO: Focus this document? */
+    invalidateWideRunsWithNonzeroOffset_DocumentWidget_(d);
+    resetWideRuns_DocumentWidget_(d); /* Selections don't support horizontal scrolling. */
+    iChangeFlags(d->flags, selecting_DocumentWidgetFlag, iTrue);
+    d->selectMark = sourceLoc_DocumentWidget_(d, pos);
+    refresh_Widget(as_Widget(d));
+}
+
 static iBool processEvent_DocumentWidget_(iDocumentWidget *d, const SDL_Event *ev) {
     iWidget *w = as_Widget(d);
     if (isMetricsChange_UserEvent(ev)) {
@@ -2593,19 +2603,28 @@ static iBool processEvent_DocumentWidget_(iDocumentWidget *d, const SDL_Event *e
         return iTrue;
     }
     /* The left mouse button. */
-    if (/*d->flags & selecting_DocumentWidgetFlag &&*/ ev->type == SDL_MOUSEBUTTONDOWN &&
-        ev->button.button == SDL_BUTTON_LEFT) {
-        if (ev->button.clicks == 2) {
-            printf("double click\n");
-        }
-        else if (ev->button.clicks == 3) {
-            printf("triple click\n");
-        }
-        fflush(stdout);
-    }
     switch (processEvent_Click(&d->click, ev)) {
         case started_ClickResult:
+            if (d->grabbedPlayer) {
+                return iTrue;
+            }
             iChangeFlags(d->flags, selecting_DocumentWidgetFlag, iFalse);
+            iChangeFlags(d->flags, selectWords_DocumentWidgetFlag, d->click.count == 2);
+            iChangeFlags(d->flags, selectLines_DocumentWidgetFlag, d->click.count >= 3);
+            /* Double/triple clicks marks the selection immediately. */
+            if (d->click.count >= 2) {
+                beginMarkingSelection_DocumentWidget_(d, d->click.startPos);
+                extendRange_Rangecc(
+                    &d->selectMark,
+                    range_String(source_GmDocument(d->doc)),
+                    bothStartAndEnd_RangeExtension |
+                        (d->click.count == 2 ? word_RangeExtension : line_RangeExtension));
+                d->initialSelectMark = d->selectMark;
+                refresh_Widget(w);
+            }
+            else {
+                d->initialSelectMark = iNullRange;
+            }
             return iTrue;
         case drag_ClickResult: {
             if (d->grabbedPlayer) {
@@ -2620,12 +2639,7 @@ static iBool processEvent_DocumentWidget_(iDocumentWidget *d, const SDL_Event *e
             }
             /* Begin selecting a range of text. */
             if (~d->flags & selecting_DocumentWidgetFlag) {
-                setFocus_Widget(NULL); /* TODO: Focus this document? */
-                invalidateWideRunsWithNonzeroOffset_DocumentWidget_(d);
-                resetWideRuns_DocumentWidget_(d); /* Selections don't support horizontal scrolling. */
-                iChangeFlags(d->flags, selecting_DocumentWidgetFlag, iTrue);
-                d->selectMark = sourceLoc_DocumentWidget_(d, d->click.startPos);
-                refresh_Widget(w);
+                beginMarkingSelection_DocumentWidget_(d, d->click.startPos);
             }
             iRangecc loc = sourceLoc_DocumentWidget_(d, pos_Click(&d->click));
             if (!d->selectMark.start) {
@@ -2634,6 +2648,23 @@ static iBool processEvent_DocumentWidget_(iDocumentWidget *d, const SDL_Event *e
             else if (loc.end) {
                 d->selectMark.end = (d->selectMark.end > d->selectMark.start ? loc.end : loc.start);
             }
+            iAssert((!d->selectMark.start && !d->selectMark.end) ||
+                    ( d->selectMark.start &&  d->selectMark.end));
+            /* Extend the selection when double/triple clicking. */
+            if (d->flags & (selectWords_DocumentWidgetFlag | selectLines_DocumentWidgetFlag)) {
+                extendRange_Rangecc(
+                    &d->selectMark,
+                    range_String(source_GmDocument(d->doc)),
+                    d->click.count == 2 ? word_RangeExtension : line_RangeExtension);
+                if (!isEmpty_Range(&d->initialSelectMark)) {
+                    if (d->selectMark.end > d->selectMark.start) {
+                        d->selectMark.start = d->initialSelectMark.start;
+                    }
+                    else if (d->selectMark.end < d->selectMark.start) {
+                        d->selectMark.start = d->initialSelectMark.end;
+                    }
+                }
+            }
 //            printf("mark %zu ... %zu\n", d->selectMark.start - cstr_String(source_GmDocument(d->doc)),
 //                   d->selectMark.end - cstr_String(source_GmDocument(d->doc)));
 //            fflush(stdout);
@@ -2727,7 +2758,8 @@ static iBool processEvent_DocumentWidget_(iDocumentWidget *d, const SDL_Event *e
                             2);
                     }
                 }
-                if (d->selectMark.start) {
+                if (d->selectMark.start && !(d->flags & (selectLines_DocumentWidgetFlag |
+                                                         selectWords_DocumentWidgetFlag))) {
                     d->selectMark = iNullRange;
                     refresh_Widget(w);
                 }
@@ -2776,16 +2808,21 @@ static void fillRange_DrawContext_(iDrawContext *d, const iGmRun *run, enum iCol
         /* Selection may be done in either direction. */
         iSwap(const char *, mark.start, mark.end);
     }
-    if ((!*isInside && (contains_Range(&run->text, mark.start) || mark.start == run->text.end)) ||
-        *isInside) {
+    if (*isInside || (contains_Range(&run->text, mark.start) ||
+                      contains_Range(&mark, run->text.start))) {
         int x = 0;
         if (!*isInside) {
-            x = advanceRange_Text(run->font, (iRangecc){ run->text.start, mark.start }).x;
+            x = advanceRange_Text(run->font,
+                                  (iRangecc){ run->text.start, iMax(run->text.start, mark.start) })
+                    .x;
         }
         int w = width_Rect(run->visBounds) - x;
-        if (contains_Range(&run->text, mark.end) || run->text.end == mark.end) {
-            w = advanceRange_Text(run->font,
-                                  !*isInside ? mark : (iRangecc){ run->text.start, mark.end }).x;
+        if (contains_Range(&run->text, mark.end) || mark.end < run->text.start) {
+            w = advanceRange_Text(
+                    run->font,
+                    !*isInside ? mark
+                               : (iRangecc){ run->text.start, iMax(run->text.start, mark.end) })
+                    .x;
             *isInside = iFalse;
         }
         else {
diff --git a/src/ui/text.c b/src/ui/text.c
index 80d3634c..6aaf40f5 100644
--- a/src/ui/text.c
+++ b/src/ui/text.c
@@ -649,7 +649,7 @@ static iChar nextChar_(const char **chPos, const char *end) {
         return 0;
     }
     iChar ch;
-    int len = decodeBytes_MultibyteChar(*chPos, end - *chPos, &ch);
+    int len = decodeBytes_MultibyteChar(*chPos, end, &ch);
     if (len <= 0) {
         (*chPos)++; /* skip it */
         return 0;
@@ -862,6 +862,7 @@ static iRect run_Font_(iFont *d, const iRunArgs *args) {
     const enum iRunMode mode        = args->mode;
     const char *        lastWordEnd = args->text.start;
     iAssert(args->xposLimit == 0 || isMeasuring_(mode));
+    iAssert(args->text.end >= args->text.start);
     if (args->continueFrom_out) {
         *args->continueFrom_out = args->text.end;
     }
diff --git a/src/ui/util.c b/src/ui/util.c
index cb9006f6..8074223b 100644
--- a/src/ui/util.c
+++ b/src/ui/util.c
@@ -164,6 +164,60 @@ iRangei union_Rangei(iRangei a, iRangei b) {
     return (iRangei){ iMin(a.start, b.start), iMax(a.end, b.end) };
 }
 
+static iBool isSelectionBreakingChar_(iChar c) {
+    return isSpace_Char(c) || (c == '@' || c == '-' || c == '/' || c == '\\' || c == ',');
+}
+
+static const char *moveBackward_(const char *pos, iRangecc bounds, int mode) {
+    iChar ch;
+    while (pos > bounds.start) {
+        int len = decodePrecedingBytes_MultibyteChar(pos, bounds.start, &ch);
+        if (len > 0) {
+            if (mode & word_RangeExtension && isSelectionBreakingChar_(ch)) break;
+            if (mode & line_RangeExtension && ch == '\n') break;
+            pos -= len;
+        }
+        else break;
+    }
+    return pos;
+}
+
+static const char *moveForward_(const char *pos, iRangecc bounds, int mode) {
+    iChar ch;
+    while (pos < bounds.end) {
+        int len = decodeBytes_MultibyteChar(pos, bounds.end, &ch);
+        if (len > 0) {
+            if (mode & word_RangeExtension && isSelectionBreakingChar_(ch)) break;
+            if (mode & line_RangeExtension && ch == '\n') break;
+            pos += len;
+        }
+        else break;
+    }
+    return pos;
+}
+
+void extendRange_Rangecc(iRangecc *d, iRangecc bounds, int mode) {
+    if (!d->start) return;
+    if (d->end >= d->start) {
+        if (mode & bothStartAndEnd_RangeExtension) {
+            d->start = moveBackward_(d->start, bounds, mode);
+            d->end   = moveForward_(d->end, bounds, mode);
+        }
+        else {
+            d->end = moveForward_(d->end, bounds, mode);
+        }
+    }
+    else {
+        if (mode & bothStartAndEnd_RangeExtension) {
+            d->start = moveForward_(d->start, bounds, mode);
+            d->end   = moveBackward_(d->end, bounds, mode);
+        }
+        else {
+            d->end = moveBackward_(d->end, bounds, mode);
+        }
+    }
+}
+
 /*----------------------------------------------------------------------------------------------*/
 
 iBool isFinished_Anim(const iAnim *d) {
diff --git a/src/ui/util.h b/src/ui/util.h
index da4d3a99..9e00e495 100644
--- a/src/ui/util.h
+++ b/src/ui/util.h
@@ -82,6 +82,14 @@ iLocalDef iBool isOverlapping_Rangei(iRangei a, iRangei b) {
     return !isEmpty_Rangei(intersect_Rangei(a, b));
 }
 
+enum iRangeExtension {
+    word_RangeExtension            = iBit(1),
+    line_RangeExtension            = iBit(2),
+    bothStartAndEnd_RangeExtension = iBit(3),
+};
+
+void        extendRange_Rangecc (iRangecc *, iRangecc bounds, int mode);
+
 /*-----------------------------------------------------------------------------------------------*/
 
 iDeclareType(Anim)