Cache GmDocuments in memory

Navigation history keeps final GmDocuments in memory for quicker restore when navigating; no need to redo layout.

Changed the color escape to Vertical Tab so Carriage Returns can be left in the source, reducing need to normalize spaces.

12 files changed, 203 insertions, 69 deletions

diff --git a/src/gmdocument.c b/src/gmdocument.c
index 466169fc..da99fd0d 100644
--- a/src/gmdocument.c
+++ b/src/gmdocument.c
@@ -47,7 +47,7 @@ iBool isDark_GmDocumentTheme(enum iGmDocumentTheme d) {
 iDeclareType(GmLink)
 
 struct Impl_GmLink {
-    iString url;
+    iString url; /* resolved */
     iRangecc urlRange; /* URL in the source */
     iRangecc labelRange; /* label in the source */
     iRangecc labelIcon; /* special icon defined in the label text */
@@ -74,8 +74,9 @@ iDefineTypeConstruction(GmLink)
 struct Impl_GmDocument {
     iObject object;
     enum iGmDocumentFormat format;
-    iString   source;
-    iString   url; /* for resolving relative links */
+    iString   unormSource; /* unnormalized source */
+    iString   source;      /* normalized source */
+    iString   url;         /* for resolving relative links */
     iString   localHost;
     iInt2     size;
     iArray    layout; /* contents of source, laid out in document space */
@@ -437,7 +438,10 @@ static void doLayout_GmDocument_(iGmDocument *d) {
         isFirstText = iFalse;
     }
     while (nextSplit_Rangecc(content, "\n", &contentLine)) {
-        iRangecc line = contentLine; /* `line` will be trimmed later; would confuse nextSplit */
+        iRangecc line = contentLine; /* `line` will be trimmed; modifying would confuse `nextSplit_Rangecc` */
+        if (*line.end == '\r') {
+            line.end--; /* trim CR always */
+        }
         iGmRun run = { .color = white_ColorId };
         enum iGmLineType type;
         float indent = 0.0f;
@@ -844,10 +848,13 @@ static void doLayout_GmDocument_(iGmDocument *d) {
             }
         }
     }
+    printf("[GmDocument] layout size: %zu runs (%zu bytes)\n",
+           size_Array(&d->layout), size_Array(&d->layout) * sizeof(iGmRun));        
 }
 
 void init_GmDocument(iGmDocument *d) {
     d->format = gemini_GmDocumentFormat;
+    init_String(&d->unormSource);
     init_String(&d->source);
     init_String(&d->url);
     init_String(&d->localHost);
@@ -878,6 +885,7 @@ void deinit_GmDocument(iGmDocument *d) {
     deinit_String(&d->localHost);
     deinit_String(&d->url);
     deinit_String(&d->source);
+    deinit_String(&d->unormSource);
 }
 
 iMedia *media_GmDocument(iGmDocument *d) {
@@ -888,6 +896,7 @@ const iMedia *constMedia_GmDocument(const iGmDocument *d) {
     return d->media;
 }
 
+#if 0
 void reset_GmDocument(iGmDocument *d) {
     clear_Media(d->media);
     clearLinks_GmDocument_(d);
@@ -896,8 +905,11 @@ void reset_GmDocument(iGmDocument *d) {
     clear_Array(&d->preMeta);
     clear_String(&d->url);
     clear_String(&d->localHost);
+    clear_String(&d->source);
+    clear_String(&d->unormSource);
     d->themeSeed = 0;
 }
+#endif
 
 static void setDerivedThemeColors_(enum iGmDocumentTheme theme) {
     set_Color(tmQuoteIcon_ColorId,
@@ -1418,6 +1430,8 @@ static void normalize_GmDocument(iGmDocument *d) {
         isPreformat = iTrue; /* Cannot be turned off. */
     }
     const int preTabWidth = 4; /* TODO: user-configurable parameter */
+    iBool wasNormalized = iFalse;
+    iBool hasTabs = iFalse;
     while (nextSplit_Rangecc(src, "\n", &line)) {
         if (isPreformat) {
             /* Replace any tab characters with spaces for visualization. */
@@ -1428,10 +1442,16 @@ static void normalize_GmDocument(iGmDocument *d) {
                     while (numSpaces-- > 0) {
                         appendCStrN_String(normalized, " ", 1);
                     }
+                    hasTabs = iTrue;
+                    wasNormalized = iTrue;
                 }
-                else if (*ch != '\r') {
+                else if (*ch != '\v') {
                     appendCStrN_String(normalized, ch, 1);
                 }
+                else {
+                    hasTabs = iTrue;
+                    wasNormalized = iTrue;
+                }
             }
             appendCStr_String(normalized, "\n");
             if (d->format == gemini_GmDocumentFormat &&
@@ -1450,7 +1470,10 @@ static void normalize_GmDocument(iGmDocument *d) {
         int spaceCount = 0;
         for (const char *ch = line.start; ch != line.end; ch++) {
             char c = *ch;
-            if (c == '\r') continue;
+            if (c == '\v') {
+                wasNormalized = iTrue;
+                continue;
+            }
             if (isNormalizableSpace_(c)) {
                 if (isPrevSpace) {
                     if (++spaceCount == 8) {
@@ -1459,9 +1482,13 @@ static void normalize_GmDocument(iGmDocument *d) {
                         popBack_Block(&normalized->chars);
                         pushBack_Block(&normalized->chars, '\t');
                     }
+                    wasNormalized = iTrue;
                     continue; /* skip repeated spaces */
                 }
-                c = ' ';
+                if (c != ' ') {
+                    c = ' ';
+                    wasNormalized = iTrue;
+                }
                 isPrevSpace = iTrue;
             }
             else {
@@ -1472,7 +1499,13 @@ static void normalize_GmDocument(iGmDocument *d) {
         }
         appendCStr_String(normalized, "\n");
     }
+    printf("hasTabs: %d\n", hasTabs);
+    printf("wasNormalized: %d\n", wasNormalized);
+    fflush(stdout);
     set_String(&d->source, collect_String(normalized));
+    printf("orig:%zu norm:%zu\n", size_String(&d->unormSource), size_String(&d->source));
+    /* normalized source has an extra newline at the end */
+    iAssert(wasNormalized || equal_String(&d->unormSource, &d->source));
 }
 
 void setUrl_GmDocument(iGmDocument *d, const iString *url) {
@@ -1483,8 +1516,18 @@ void setUrl_GmDocument(iGmDocument *d, const iString *url) {
     updateIconBasedOnUrl_GmDocument_(d);
 }
 
-void setSource_GmDocument(iGmDocument *d, const iString *source, int width) {
-    set_String(&d->source, source);
+void setSource_GmDocument(iGmDocument *d, const iString *source, int width,
+                          enum iGmDocumentUpdate updateType) {
+    printf("[GmDocument] source update (%zu bytes), width:%d, final:%d\n",
+           size_String(source), width, updateType == final_GmDocumentUpdate);
+    if (size_String(source) == size_String(&d->unormSource)) {
+        iAssert(equal_String(source, &d->unormSource));
+        printf("[GmDocument] source is unchanged!\n");
+        return; /* Nothing to do. */
+    }
+    set_String(&d->unormSource, source);
+    /* Normalize. */
+    set_String(&d->source, &d->unormSource);
     if (isNormalized_GmDocument_(d)) {
         normalize_GmDocument(d);
     }
@@ -1586,6 +1629,14 @@ const iString *source_GmDocument(const iGmDocument *d) {
     return &d->source;
 }
 
+size_t memorySize_GmDocument(const iGmDocument *d) {
+    return size_String(&d->unormSource) +
+           size_String(&d->source) +
+           size_Array(&d->layout) * sizeof(iGmRun) +
+           size_Array(&d->links)  * sizeof(iGmLink) +
+           memorySize_Media(d->media);
+}
+
 iRangecc findText_GmDocument(const iGmDocument *d, const iString *text, const char *start) {
     const char * src      = constBegin_String(&d->source);
     const size_t startPos = (start ? start - src : 0);
diff --git a/src/gmdocument.h b/src/gmdocument.h
index 574f0acf..1e54a16a 100644
--- a/src/gmdocument.h
+++ b/src/gmdocument.h
@@ -125,12 +125,12 @@ enum iGmRunMediaType {
 
 struct Impl_GmRun {
     iRangecc  text;
+    iRect     bounds;    /* used for hit testing, may extend to edges */
+    iRect     visBounds; /* actual visual bounds */
     uint8_t   font;
     uint8_t   color;
     uint8_t   flags;
     uint8_t   mediaType;
-    iRect     bounds;    /* used for hit testing, may extend to edges */
-    iRect     visBounds; /* actual visual bounds */
     uint16_t  preId;     /* preformatted block ID (sequential) */
     iGmLinkId linkId;    /* zero for non-links */
     uint16_t  mediaId;   /* zero if not an image */
@@ -160,6 +160,11 @@ enum iGmDocumentBanner {
     certificateWarning_GmDocumentBanner,
 };
 
+enum iGmDocumentUpdate {
+    partial_GmDocumentUpdate, /* appending more content */
+    final_GmDocumentUpdate,   /* process all lines, including the last one if not terminated */
+};
+
 void    setThemeSeed_GmDocument (iGmDocument *, const iBlock *seed);
 void    setFormat_GmDocument    (iGmDocument *, enum iGmDocumentFormat format);
 void    setBanner_GmDocument    (iGmDocument *, enum iGmDocumentBanner type);
@@ -167,10 +172,11 @@ void    setWidth_GmDocument     (iGmDocument *, int width);
 void    redoLayout_GmDocument   (iGmDocument *);
 iBool   updateOpenURLs_GmDocument(iGmDocument *);
 void    setUrl_GmDocument       (iGmDocument *, const iString *url);
-void    setSource_GmDocument    (iGmDocument *, const iString *source, int width);
+void    setSource_GmDocument    (iGmDocument *, const iString *source, int width,
+                                 enum iGmDocumentUpdate updateType);
 void    foldPre_GmDocument      (iGmDocument *, uint16_t preId);
 
-void    reset_GmDocument        (iGmDocument *); /* free images */
+//void    reset_GmDocument        (iGmDocument *); /* free images */
 
 typedef void (*iGmDocumentRenderFunc)(void *, const iGmRun *);
 
@@ -190,6 +196,7 @@ enum iGmDocumentBanner bannerType_GmDocument(const iGmDocument *);
 const iString * bannerText_GmDocument       (const iGmDocument *);
 const iArray *  headings_GmDocument         (const iGmDocument *); /* array of GmHeadings */
 const iString * source_GmDocument           (const iGmDocument *);
+size_t          memorySize_GmDocument       (const iGmDocument *); /* bytes */
 
 iRangecc        findText_GmDocument                 (const iGmDocument *, const iString *text, const char *start);
 iRangecc        findTextBefore_GmDocument           (const iGmDocument *, const iString *text, const char *before);
diff --git a/src/history.c b/src/history.c
index 9f4e415b..58ffa5c4 100644
--- a/src/history.c
+++ b/src/history.c
@@ -34,11 +34,13 @@ static const size_t maxStack_History_ = 50; /* back/forward navigable items */
 
 void init_RecentUrl(iRecentUrl *d) {
     init_String(&d->url);
-    d->normScrollY = 0;
+    d->normScrollY    = 0;
     d->cachedResponse = NULL;
+    d->cachedDoc      = NULL;
 }
 
 void deinit_RecentUrl(iRecentUrl *d) {
+    iRelease(d->cachedDoc);
     deinit_String(&d->url);
     delete_GmResponse(d->cachedResponse);
 }
@@ -48,11 +50,29 @@ iDefineTypeConstruction(RecentUrl)
 iRecentUrl *copy_RecentUrl(const iRecentUrl *d) {
     iRecentUrl *copy = new_RecentUrl();
     set_String(&copy->url, &d->url);
-    copy->normScrollY = d->normScrollY;
+    copy->normScrollY    = d->normScrollY;
     copy->cachedResponse = d->cachedResponse ? copy_GmResponse(d->cachedResponse) : NULL;
+    copy->cachedDoc      = ref_Object(d->cachedDoc);
     return copy;
 }
 
+size_t cacheSize_RecentUrl(const iRecentUrl *d) {
+    size_t size = 0;
+    if (d->cachedResponse) {
+        size += size_String(&d->cachedResponse->meta);
+        size += size_Block(&d->cachedResponse->body);
+    }
+    return size;    
+}
+
+size_t memorySize_RecentUrl(const iRecentUrl *d) {
+    size_t size = cacheSize_RecentUrl(d);
+    if (d->cachedDoc) {
+        size += memorySize_GmDocument(d->cachedDoc);
+    }
+    return size;
+}
+
 /*----------------------------------------------------------------------------------------------*/
 
 struct Impl_History {
@@ -92,20 +112,31 @@ iString *debugInfo_History(const iHistory *d) {
     iString *str = new_String();
     format_String(str,
                   "```\n"
-                  "Idx |    Size | SP%% | URL\n"
-                  "----+---------+-----+-----\n");
-    size_t totalSize = 0;
+                  "Idx |   Cache |   Memory | SP%% | URL\n"
+                  "----+---------+----------+-----+-----\n");
+    size_t totalCache = 0;
+    size_t totalMemory = 0;
     iConstForEach(Array, i, &d->recent) {
         const iRecentUrl *item = i.value;
         appendFormat_String(
             str, " %2zu | ", size_Array(&d->recent) - index_ArrayConstIterator(&i) - 1);
-        if (item->cachedResponse) {
-            appendFormat_String(str, "%7zu", size_Block(&item->cachedResponse->body));
-            totalSize += size_Block(&item->cachedResponse->body);
+        const size_t cacheSize = cacheSize_RecentUrl(item);
+        const size_t memSize   = memorySize_RecentUrl(item);
+        if (cacheSize) {
+            appendFormat_String(str, "%7zu", cacheSize);
+            totalCache += cacheSize;
         }
         else {
             appendFormat_String(str, "     --");
         }
+        appendCStr_String(str, " | ");
+        if (memSize) {
+            appendFormat_String(str, "%8zu", memSize);
+            totalMemory += memSize;
+        }
+        else {
+            appendFormat_String(str, "      --");
+        }
         appendFormat_String(str,
                             " | %3d | %s\n",
                             iRound(100.0f * item->normScrollY),
@@ -114,8 +145,10 @@ iString *debugInfo_History(const iHistory *d) {
     appendFormat_String(str, "\n```\n");
     appendFormat_String(str,
                         "Total cached data: %.3f MB\n"
+                        "Total memory usage: %.3f MB\n"
                         "Navigation position: %zu\n\n",
-                        totalSize / 1.0e6f,
+                        totalCache / 1.0e6f,
+                        totalMemory / 1.0e6f,
                         d->recentPos);
     return str;
 }
@@ -301,14 +334,22 @@ void setCachedResponse_History(iHistory *d, const iGmResponse *response) {
     unlock_Mutex(d->mtx);
 }
 
+void setCachedDocument_History(iHistory *d, iGmDocument *doc) {
+    lock_Mutex(d->mtx);
+    iRecentUrl *item = mostRecentUrl_History(d);
+    if (item && item->cachedDoc != doc) {
+        iRelease(item->cachedDoc);
+        item->cachedDoc = ref_Object(doc);
+    }
+    unlock_Mutex(d->mtx);
+}
+
 size_t cacheSize_History(const iHistory *d) {
     size_t cached = 0;
     lock_Mutex(d->mtx);
     iConstForEach(Array, i, &d->recent) {
         const iRecentUrl *url = i.value;
-        if (url->cachedResponse) {
-            cached += size_Block(&url->cachedResponse->body);
-        }
+        cached += cacheSize_RecentUrl(url);
     }
     unlock_Mutex(d->mtx);
     return cached;
@@ -335,9 +376,9 @@ size_t pruneLeastImportant_History(iHistory *d) {
     lock_Mutex(d->mtx);
     iConstForEach(Array, i, &d->recent) {
         const iRecentUrl *url = i.value;
-        if (url->cachedResponse) {
+        if (url->cachedResponse || url->cachedDoc) {
             const double urlScore =
-                size_Block(&url->cachedResponse->body) *
+                cacheSize_RecentUrl(url) *
                 pow(secondsSince_Time(&now, &url->cachedResponse->when) / 60.0, 1.25);
             if (urlScore > score) {
                 chosen = index_ArrayConstIterator(&i);
@@ -347,9 +388,10 @@ size_t pruneLeastImportant_History(iHistory *d) {
     }
     if (chosen != iInvalidPos) {
         iRecentUrl *url = at_Array(&d->recent, chosen);
-        delta = size_Block(&url->cachedResponse->body);
+        delta = cacheSize_RecentUrl(url);
         delete_GmResponse(url->cachedResponse);
         url->cachedResponse = NULL;
+        iReleasePtr(&url->cachedDoc);
     }
     unlock_Mutex(d->mtx);
     return delta;
diff --git a/src/history.h b/src/history.h
index 164a61d6..1acf7049 100644
--- a/src/history.h
+++ b/src/history.h
@@ -22,6 +22,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
 
 #pragma once
 
+#include "gmdocument.h"
 #include "gmrequest.h"
 
 #include <the_Foundation/ptrarray.h>
@@ -37,6 +38,7 @@ struct Impl_RecentUrl {
     iString      url;
     float        normScrollY;    /* normalized to document height */
     iGmResponse *cachedResponse; /* kept in memory for quicker back navigation */
+    iGmDocument *cachedDoc;      /* cached copy of the presentation: layout and media (not serialized) */
 };
 
 /*----------------------------------------------------------------------------------------------*/
@@ -51,6 +53,7 @@ void        clear_History               (iHistory *);
 void        add_History                 (iHistory *, const iString *url);
 void        replace_History             (iHistory *, const iString *url);
 void        setCachedResponse_History   (iHistory *, const iGmResponse *response);
+void        setCachedDocument_History   (iHistory *, iGmDocument *doc);
 iBool       goBack_History              (iHistory *);
 iBool       goForward_History           (iHistory *);
 iRecentUrl *recentUrl_History           (iHistory *, size_t pos);
diff --git a/src/macos.m b/src/macos.m
index 61507b6f..709a97f7 100644
--- a/src/macos.m
+++ b/src/macos.m
@@ -479,7 +479,7 @@ void insertMenuItems_MacOS(const char *menuLabel, int atIndex, const iMenuItem *
     [menu setAutoenablesItems:NO];
     for (size_t i = 0; i < count; ++i) {
         const char *label = translateCStr_Lang(items[i].label);
-        if (label[0] == '\r') {
+        if (label[0] == '\v') {
             /* Skip the formatting escape. */
             label += 2;
         }
diff --git a/src/media.c b/src/media.c
index 1313b7da..2ec2109d 100644
--- a/src/media.c
+++ b/src/media.c
@@ -261,6 +261,11 @@ void clear_Media(iMedia *d) {
     clear_PtrArray(&d->downloads);
 }
 
+size_t memorySize_Media(const iMedia *d) {
+    /* TODO: Calculate the actual memory use. */
+    return 0; 
+}
+
 iBool setDownloadUrl_Media(iMedia *d, iGmLinkId linkId, const iString *url) {
     iGmDownload *dl       = NULL;
     iMediaId     existing = findLinkDownload_Media(d, linkId);
diff --git a/src/media.h b/src/media.h
index 7cc941d0..c6973b79 100644
--- a/src/media.h
+++ b/src/media.h
@@ -50,6 +50,8 @@ void    clear_Media             (iMedia *);
 iBool   setDownloadUrl_Media    (iMedia *, uint16_t linkId, const iString *url);
 iBool   setData_Media           (iMedia *, uint16_t linkId, const iString *mime, const iBlock *data, int flags);
 
+size_t  memorySize_Media        (const iMedia *);
+
 iMediaId        findLinkImage_Media (const iMedia *, uint16_t linkId);
 iBool           imageInfo_Media     (const iMedia *, iMediaId imageId, iGmMediaInfo *info_out);
 iInt2           imageSize_Media     (const iMedia *, iMediaId imageId);
diff --git a/src/ui/color.c b/src/ui/color.c
index 6cbbdf28..0a177a8a 100644
--- a/src/ui/color.c
+++ b/src/ui/color.c
@@ -468,12 +468,12 @@ const char *escape_Color(int color) {
         return esc[color];
     }
     /* TODO: Conflict with format strings! "%" (37) may be used as the color value. */
-    /* Double-\r is used for range extension. */
+    /* Double-\v is used for range extension. */
     if (color + asciiBase_ColorEscape > 127) {
         iAssert(color - asciiExtended_ColorEscape + asciiBase_ColorEscape <= 127);
-        return format_CStr("\r\r%c", color - asciiExtended_ColorEscape + asciiBase_ColorEscape);
+        return format_CStr("\v\v%c", color - asciiExtended_ColorEscape + asciiBase_ColorEscape);
     }
-    return format_CStr("\r%c", color + asciiBase_ColorEscape);
+    return format_CStr("\v%c", color + asciiBase_ColorEscape);
 }
 
 iHSLColor setSat_HSLColor(iHSLColor d, float sat) {
diff --git a/src/ui/color.h b/src/ui/color.h
index d2fa3c00..aafc1794 100644
--- a/src/ui/color.h
+++ b/src/ui/color.h
@@ -187,26 +187,26 @@ iLocalDef iBool isRegularText_ColorId(enum iColorId d) {
 #define asciiBase_ColorEscape       33
 #define asciiExtended_ColorEscape   (128 - asciiBase_ColorEscape)
 
-#define restore_ColorEscape         "\r\x24" /* ASCII Cancel */
-#define black_ColorEscape           "\r!"
-#define gray25_ColorEscape          "\r\""
-#define gray50_ColorEscape          "\r#"
-#define gray75_ColorEscape          "\r$"
-#define white_ColorEscape           "\r%"
-#define brown_ColorEscape           "\r&"
-#define orange_ColorEscape          "\r'"
-#define teal_ColorEscape            "\r("
-#define cyan_ColorEscape            "\r)"
-#define yellow_ColorEscape          "\r*"
-#define red_ColorEscape             "\r+"
-#define magenta_ColorEscape         "\r,"
-#define blue_ColorEscape            "\r-"
-#define green_ColorEscape           "\r."
-#define uiText_ColorEscape          "\r4"
-#define uiTextAction_ColorEscape    "\r<"
-#define uiTextCaution_ColorEscape   "\r="
-#define uiTextStrong_ColorEscape    "\r:"
-#define uiHeading_ColorEscape       "\rR"
+#define restore_ColorEscape         "\v\x24" /* ASCII Cancel */
+#define black_ColorEscape           "\v!"
+#define gray25_ColorEscape          "\v\""
+#define gray50_ColorEscape          "\v#"
+#define gray75_ColorEscape          "\v$"
+#define white_ColorEscape           "\v%"
+#define brown_ColorEscape           "\v&"
+#define orange_ColorEscape          "\v'"
+#define teal_ColorEscape            "\v("
+#define cyan_ColorEscape            "\v)"
+#define yellow_ColorEscape          "\v*"
+#define red_ColorEscape             "\v+"
+#define magenta_ColorEscape         "\v,"
+#define blue_ColorEscape            "\v-"
+#define green_ColorEscape           "\v."
+#define uiText_ColorEscape          "\v4"
+#define uiTextAction_ColorEscape    "\v<"
+#define uiTextCaution_ColorEscape   "\v="
+#define uiTextStrong_ColorEscape    "\v:"
+#define uiHeading_ColorEscape       "\vR"
 
 iDeclareType(Color)
 iDeclareType(HSLColor)
diff --git a/src/ui/documentwidget.c b/src/ui/documentwidget.c
index 0314757f..048f8ce4 100644
--- a/src/ui/documentwidget.c
+++ b/src/ui/documentwidget.c
@@ -975,13 +975,11 @@ iBool isPinned_DocumentWidget_(const iDocumentWidget *d) {
 
 static void showOrHidePinningIndicator_DocumentWidget_(iDocumentWidget *d) {
     iWidget *w = as_Widget(d);
-    showCollapsed_Widget(findChild_Widget(root_Widget(as_Widget(d)), "document.pinned"),
+    showCollapsed_Widget(findChild_Widget(root_Widget(w), "document.pinned"),
                          isPinned_DocumentWidget_(d));
 }
 
-void setSource_DocumentWidget(iDocumentWidget *d, const iString *source) {
-    setUrl_GmDocument(d->doc, d->mod.url);
-    setSource_GmDocument(d->doc, source, documentWidth_DocumentWidget_(d));
+static void documentWasChanged_DocumentWidget_(iDocumentWidget *d) {
     documentRunsInvalidated_DocumentWidget_(d);
     updateWindowTitle_DocumentWidget_(d);
     updateVisible_DocumentWidget_(d);
@@ -997,7 +995,23 @@ void setSource_DocumentWidget(iDocumentWidget *d, const iString *source) {
             d->flags |= otherRootByDefault_DocumentWidgetFlag;
         }
     }
-    showOrHidePinningIndicator_DocumentWidget_(d);
+    showOrHidePinningIndicator_DocumentWidget_(d);    
+}
+
+void setSource_DocumentWidget(iDocumentWidget *d, const iString *source) {
+    setUrl_GmDocument(d->doc, d->mod.url);
+    setSource_GmDocument(d->doc,
+                         source,
+                         documentWidth_DocumentWidget_(d),
+                         isFinished_GmRequest(d->request) ? final_GmDocumentUpdate
+                                                          : partial_GmDocumentUpdate);
+    documentWasChanged_DocumentWidget_(d);
+}
+
+static void replaceDocument_DocumentWidget_(iDocumentWidget *d, iGmDocument *newDoc) {
+    iRelease(d->doc);
+    d->doc = ref_Object(newDoc);
+    documentWasChanged_DocumentWidget_(d);
 }
 
 static void updateTheme_DocumentWidget_(iDocumentWidget *d) {
@@ -1063,13 +1077,13 @@ static void showErrorPage_DocumentWidget_(iDocumentWidget *d, enum iGmStatusCode
     setBanner_GmDocument(d->doc, useBanner ? bannerType_DocumentWidget_(d) : none_GmDocumentBanner);
     setFormat_GmDocument(d->doc, gemini_GmDocumentFormat);
     translate_Lang(src);
+    d->state = ready_RequestState;
     setSource_DocumentWidget(d, src);
     updateTheme_DocumentWidget_(d);
     reset_SmoothScroll(&d->scrollY);
     init_Anim(&d->sideOpacity, 0);
     init_Anim(&d->altTextOpacity, 0);
     resetWideRuns_DocumentWidget_(d);
-    d->state = ready_RequestState;
 }
 
 static void updateFetchProgress_DocumentWidget_(iDocumentWidget *d) {
@@ -1174,7 +1188,9 @@ static void postProcessRequestContent_DocumentWidget_(iDocumentWidget *d, iBool
     }
 }
 
-static void updateDocument_DocumentWidget_(iDocumentWidget *d, const iGmResponse *response,
+static void updateDocument_DocumentWidget_(iDocumentWidget *d,
+                                           const iGmResponse *response,
+                                           iGmDocument *cachedDoc,
                                            const iBool isInitialUpdate) {
     if (d->state == ready_RequestState) {
         return;
@@ -1247,6 +1263,7 @@ static void updateDocument_DocumentWidget_(iDocumentWidget *d, const iGmResponse
                     docFormat = gemini_GmDocumentFormat;
                     setRange_String(&d->sourceMime, param);
                     const iGmLinkId imgLinkId = 1; /* there's only the one link */
+                    /* TODO: Do the image loading in `postProcessRequestContent_DocumentWidget_()` */
                     if ((isAudio && isInitialUpdate) || (!isAudio && isRequestFinished)) {
                         const char *linkTitle =
                             startsWith_String(mimeStr, "image/") ? "Image" : "Audio";
@@ -1300,7 +1317,10 @@ static void updateDocument_DocumentWidget_(iDocumentWidget *d, const iGmResponse
                            collect_String(decode_Block(&str.chars, cstr_Rangecc(charset))));
             }
         }
-        if (setSource) {
+        if (cachedDoc) {
+            replaceDocument_DocumentWidget_(d, cachedDoc);
+        }
+        else if (setSource) {
             setSource_DocumentWidget(d, &str);
         }
         deinit_String(&str);
@@ -1386,7 +1406,8 @@ static iBool updateFromHistory_DocumentWidget_(iDocumentWidget *d) {
         clear_ObjectList(d->media);
         delete_Gempub(d->sourceGempub);
         d->sourceGempub = NULL;
-        reset_GmDocument(d->doc);
+        iRelease(d->doc);
+        d->doc = new_GmDocument();
         resetWideRuns_DocumentWidget_(d);
         d->state = fetching_RequestState;
         /* Do the fetch. */ {
@@ -1397,10 +1418,11 @@ static iBool updateFromHistory_DocumentWidget_(iDocumentWidget *d) {
             d->sourceStatus = success_GmStatusCode;
             format_String(&d->sourceHeader, cstr_Lang("pageinfo.header.cached"));
             set_Block(&d->sourceContent, &resp->body);
-            updateDocument_DocumentWidget_(d, resp, iTrue);
-            postProcessRequestContent_DocumentWidget_(d, iTrue);
+            updateDocument_DocumentWidget_(d, resp, recent->cachedDoc, iTrue);
+            setCachedDocument_History(d->mod.history, d->doc);
         }
         d->state = ready_RequestState;
+        postProcessRequestContent_DocumentWidget_(d, iTrue);
         init_Anim(&d->altTextOpacity, 0);
         reset_SmoothScroll(&d->scrollY);
         init_Anim(&d->scrollY.pos, d->initNormScrollY * size_GmDocument(d->doc).y);
@@ -1587,11 +1609,12 @@ static void checkResponse_DocumentWidget_(iDocumentWidget *d) {
             }
             case categorySuccess_GmStatusCode:
                 reset_SmoothScroll(&d->scrollY);
-                reset_GmDocument(d->doc); /* new content incoming */
+                iRelease(d->doc); /* new content incoming */
+                d->doc = new_GmDocument();
                 delete_Gempub(d->sourceGempub);
                 d->sourceGempub = NULL;
                 resetWideRuns_DocumentWidget_(d);
-                updateDocument_DocumentWidget_(d, resp, iTrue);
+                updateDocument_DocumentWidget_(d, resp, NULL, iTrue);
                 break;
             case categoryRedirect_GmStatusCode:
                 if (isEmpty_String(&resp->meta)) {
@@ -1642,7 +1665,7 @@ static void checkResponse_DocumentWidget_(iDocumentWidget *d) {
         switch (category_GmStatusCode(statusCode)) {
             case categorySuccess_GmStatusCode:
                 /* More content available. */
-                updateDocument_DocumentWidget_(d, resp, iFalse);
+                updateDocument_DocumentWidget_(d, resp, NULL, iFalse);
                 break;
             default:
                 break;
@@ -2258,6 +2281,7 @@ static iBool handleCommand_DocumentWidget_(iDocumentWidget *d, const char *cmd)
                 (startsWithCase_String(meta_GmRequest(d->request), "text/") ||
                  !cmp_String(&d->sourceMime, mimeType_Gempub))) {
                 setCachedResponse_History(d->mod.history, lockResponse_GmRequest(d->request));
+                setCachedDocument_History(d->mod.history, d->doc); /* keeps a ref */
                 unlockResponse_GmRequest(d->request);
             }
         }
diff --git a/src/ui/labelwidget.c b/src/ui/labelwidget.c
index 5d0f0041..a7aa6391 100644
--- a/src/ui/labelwidget.c
+++ b/src/ui/labelwidget.c
@@ -196,7 +196,7 @@ static void getColors_LabelWidget_(const iLabelWidget *d, int *bg, int *fg, int
         }
     }
     int colorEscape = none_ColorId;
-    if (startsWith_String(&d->label, "\r")) {
+    if (startsWith_String(&d->label, "\v")) {
         colorEscape = cstr_String(&d->label)[1] - asciiBase_ColorEscape; /* TODO: can be two bytes long */
     }
     if (isHover_Widget(w)) {
diff --git a/src/ui/text.c b/src/ui/text.c
index 9532e35a..8cf4464e 100644
--- a/src/ui/text.c
+++ b/src/ui/text.c
@@ -946,10 +946,10 @@ static iRect run_Font_(iFont *d, const iRunArgs *args) {
                 prevCh = 0;
                 continue;
             }
-            if (ch == '\r') { /* color change */
+            if (ch == '\v') { /* color change */
                 iChar esc = nextChar_(&chPos, args->text.end);
                 int colorNum = args->color;
-                if (esc == '\r') { /* Extended range. */
+                if (esc == '\v') { /* Extended range. */
                     esc = nextChar_(&chPos, args->text.end) + asciiExtended_ColorEscape;
                     colorNum = esc - asciiBase_ColorEscape;
                 }