Added a page translation service

This is quite experimental.

The page contents are sent to an instance of LibreTranslate (powered by Argos Translate), which may or may not successfully translate the contents without mangling the gemtext markup.

7 files changed, 527 insertions, 18 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 35c7cb98..b4d7e659 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -158,6 +158,8 @@ set (SOURCES
     src/ui/text.h
     src/ui/touch.c
     src/ui/touch.h
+    src/ui/translation.c
+    src/ui/translation.h
     src/ui/util.c
     src/ui/util.h
     src/ui/visbuf.c
diff --git a/src/ui/documentwidget.c b/src/ui/documentwidget.c
index 79e8b727..a468e2df 100644
--- a/src/ui/documentwidget.c
+++ b/src/ui/documentwidget.c
@@ -43,6 +43,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
 #include "paint.h"
 #include "mediaui.h"
 #include "scrollwidget.h"
+#include "translation.h"
 #include "util.h"
 #include "visbuf.h"
 #include "visited.h"
@@ -218,6 +219,7 @@ struct Impl_DocumentWidget {
     iPtrSet *      invalidRuns;
     SDL_Texture *  sideIconBuf;
     iTextBuf *     timestampBuf;
+    iTranslation * translation;
 };
 
 iDefineObjectConstruction(DocumentWidget)
@@ -273,6 +275,7 @@ void init_DocumentWidget(iDocumentWidget *d) {
     d->playerMenu   = NULL;
     d->sideIconBuf  = NULL;
     d->timestampBuf = NULL;
+    d->translation  = NULL;
     addChildFlags_Widget(w,
                          iClob(new_IndicatorWidget()),
                          resizeToParentWidth_WidgetFlag | resizeToParentHeight_WidgetFlag);
@@ -289,6 +292,7 @@ void init_DocumentWidget(iDocumentWidget *d) {
 }
 
 void deinit_DocumentWidget(iDocumentWidget *d) {
+    delete_Translation(d->translation);
     if (d->sideIconBuf) {
         SDL_DestroyTexture(d->sideIconBuf);
     }
@@ -751,7 +755,7 @@ static void documentRunsInvalidated_DocumentWidget_(iDocumentWidget *d) {
     d->lastVisibleRun  = NULL;
 }
 
-static void setSource_DocumentWidget_(iDocumentWidget *d, const iString *source) {
+void setSource_DocumentWidget(iDocumentWidget *d, const iString *source) {
     setUrl_GmDocument(d->doc, d->mod.url);
     setSource_GmDocument(d->doc, source, documentWidth_DocumentWidget_(d));
     documentRunsInvalidated_DocumentWidget_(d);
@@ -825,7 +829,7 @@ static void showErrorPage_DocumentWidget_(iDocumentWidget *d, enum iGmStatusCode
     }
     setBanner_GmDocument(d->doc, useBanner ? bannerType_DocumentWidget_(d) : none_GmDocumentBanner);
     setFormat_GmDocument(d->doc, gemini_GmDocumentFormat);
-    setSource_DocumentWidget_(d, src);
+    setSource_DocumentWidget(d, src);
     updateTheme_DocumentWidget_(d);
     init_Anim(&d->scrollY, 0);
     init_Anim(&d->sideOpacity, 0);
@@ -947,7 +951,7 @@ static void updateDocument_DocumentWidget_(iDocumentWidget *d, const iGmResponse
             }
         }
         if (setSource) {
-            setSource_DocumentWidget_(d, &str);
+            setSource_DocumentWidget(d, &str);
         }
         deinit_String(&str);
     }
@@ -1777,6 +1781,20 @@ static iBool handleCommand_DocumentWidget_(iDocumentWidget *d, const char *cmd)
         cacheDocumentGlyphs_DocumentWidget_(d);
         return iFalse;
     }
+    else if (equalWidget_Command(cmd, w, "document.translate")) {
+        if (!d->translation) {
+            d->translation = new_Translation(d);
+        }
+        return iTrue;
+    }
+    else if (startsWith_CStr(cmd, "translation.") && d->translation) {
+        const iBool wasHandled = handleCommand_Translation(d->translation, cmd);
+        if (isFinished_Translation(d->translation)) {
+            delete_Translation(d->translation);
+            d->translation = NULL;
+        }
+        return wasHandled;
+    }
     else if (equal_Command(cmd, "media.updated") || equal_Command(cmd, "media.finished")) {
         return handleMediaCommand_DocumentWidget_(d, cmd);
     }
@@ -2524,9 +2542,10 @@ static iBool processEvent_DocumentWidget_(iDocumentWidget *d, const SDL_Event *e
                             { star_Icon " Subscribe to Page...", subscribeToPage_KeyModifier, "feeds.subscribe" },
                             { "---", 0, 0, NULL },
                             { book_Icon " Import Links as Bookmarks...", 0, 0, "bookmark.links confirm:1" },
+                            { "Translate...", 0, 0, "document.translate" },
                             { "---", 0, 0, NULL },
                             { "Copy Page URL", 0, 0, "document.copylink" } },
-                        11);
+                        12);
                     if (isEmpty_Range(&d->selectMark)) {
                         pushBackN_Array(
                             &items,
diff --git a/src/ui/documentwidget.h b/src/ui/documentwidget.h
index f922e7ea..12603437 100644
--- a/src/ui/documentwidget.h
+++ b/src/ui/documentwidget.h
@@ -49,5 +49,6 @@ void    setUrl_DocumentWidget           (iDocumentWidget *, const iString *url);
 void    setUrlFromCache_DocumentWidget  (iDocumentWidget *, const iString *url, iBool isFromCache);
 void    setInitialScroll_DocumentWidget (iDocumentWidget *, float normScrollY); /* set after content received */
 void    setRedirectCount_DocumentWidget (iDocumentWidget *, int count);
+void    setSource_DocumentWidget        (iDocumentWidget *, const iString *sourceText);
 
 void    updateSize_DocumentWidget       (iDocumentWidget *);
diff --git a/src/ui/translation.c b/src/ui/translation.c
new file mode 100644
index 00000000..cfb6eb79
--- /dev/null
+++ b/src/ui/translation.c
@@ -0,0 +1,360 @@
+/* Copyright 2021 Jaakko Keränen <jaakko.keranen@iki.fi>
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
+
+#include "translation.h"
+
+#include "app.h"
+#include "gmdocument.h"
+#include "ui/command.h"
+#include "ui/documentwidget.h"
+#include "ui/labelwidget.h"
+#include "ui/paint.h"
+#include "ui/util.h"
+
+#include <the_Foundation/regexp.h>
+#include <SDL_timer.h>
+#include <math.h>
+
+/*----------------------------------------------------------------------------------------------*/
+
+iDeclareWidgetClass(TranslationProgressWidget)
+iDeclareObjectConstruction(TranslationProgressWidget)
+
+iDeclareType(Sprite)
+
+struct Impl_Sprite {
+    iInt2 pos;
+    iInt2 size;
+    int color;
+    int xoff;
+    iString text;
+};
+
+struct Impl_TranslationProgressWidget {
+    iWidget widget;
+    uint32_t startTime;
+    int font;
+    iArray sprites;
+};
+
+void init_TranslationProgressWidget(iTranslationProgressWidget *d) {
+    iWidget *w = &d->widget;
+    init_Widget(w);
+    setId_Widget(w, "xlt.progress");
+    init_Array(&d->sprites, sizeof(iSprite));
+    d->startTime = SDL_GetTicks();
+    /* Set up some letters to animate. */
+    const char *chars = "ARGOS";
+    const size_t n = strlen(chars);
+    resize_Array(&d->sprites, n);
+    d->font = uiContentBold_FontId;
+    const int width = lineHeight_Text(d->font);
+    const int gap = gap_Text / 2;
+    int x = (int) (n * width + (n - 1) * gap) / -2;
+    const int y = -lineHeight_Text(d->font) / 2;
+    for (size_t i = 0; i < n; i++) {
+        iSprite *spr = at_Array(&d->sprites, i);
+        spr->pos = init_I2(x, y);
+        spr->color = 0;
+        init_String(&spr->text);
+        appendChar_String(&spr->text, chars[i]);
+        spr->xoff = (width - advanceRange_Text(d->font, range_String(&spr->text)).x) / 2;
+        spr->size = init_I2(width, lineHeight_Text(d->font));
+        x += width + gap;
+    }
+}
+
+void deinit_TranslationProgressWidget(iTranslationProgressWidget *d) {
+    iForEach(Array, i, &d->sprites) {
+        iSprite *spr = i.value;
+        deinit_String(&spr->text);
+    }
+    deinit_Array(&d->sprites);
+}
+
+iDefineObjectConstruction(TranslationProgressWidget)
+
+static void draw_TranslationProgressWidget_(const iTranslationProgressWidget *d) {
+    const iWidget *w = &d->widget;
+    const float t = (float) (SDL_GetTicks() - d->startTime) / 1000.0f;
+    const iRect bounds = bounds_Widget(w);
+    iPaint p;
+    init_Paint(&p);
+    const iInt2 mid = mid_Rect(bounds);
+    SDL_SetRenderDrawBlendMode(renderer_Window(get_Window()), SDL_BLENDMODE_BLEND);
+    iConstForEach(Array, i, &d->sprites) {
+        const int index = index_ArrayConstIterator(&i);
+        const float angle = (float) index;
+        const iSprite *spr = i.value;
+        const float opacity = iClamp(t - index * 0.5f, 0.0, 1.0f);
+        int bg = uiBackgroundSelected_ColorId;
+        int fg = uiTextSelected_ColorId;
+        iInt2 pos = add_I2(mid, spr->pos);
+        pos.y += sin(angle + t) * spr->size.y * iClamp(t * 0.25f - 0.3f, 0.0f, 1.0f);
+        if (bg >= 0) {
+            p.alpha = opacity * 255;
+            fillRect_Paint(&p, (iRect){ pos, spr->size }, bg);
+        }
+        if (fg >= 0) {
+            setOpacity_Text(opacity * 2);
+            drawRange_Text(d->font, addX_I2(pos, spr->xoff), fg, range_String(&spr->text));
+        }
+    }
+    setOpacity_Text(1.0f);
+    SDL_SetRenderDrawBlendMode(renderer_Window(get_Window()), SDL_BLENDMODE_NONE);
+}
+
+static iBool processEvent_TranslationProgressWidget_(iTranslationProgressWidget *d,
+                                                     const SDL_Event *ev) {
+    iUnused(d, ev);
+    return iFalse;
+}
+
+iBeginDefineSubclass(TranslationProgressWidget, Widget)
+    .draw         = (iAny *) draw_TranslationProgressWidget_,
+    .processEvent = (iAny *) processEvent_TranslationProgressWidget_,
+ iEndDefineSubclass(TranslationProgressWidget)
+
+/*----------------------------------------------------------------------------------------------*/
+
+iDefineTypeConstructionArgs(Translation, (iDocumentWidget *doc), doc)
+
+static const char *   translationServiceHost = "xlt.skyjake.fi";
+static const uint16_t translationServicePort = 443;
+
+static const char *doubleArrowSymbol    = "\u20e2"; /* prevent getting mangled */
+static const char *tripleBacktickSymbol = "\u20e3";
+static const char *h1Symbol             = "\u20e4";
+static const char *h2Symbol             = "\u20e5";
+static const char *h3Symbol             = "\u20e6";
+
+static iString *quote_String_(const iString *d) {
+    iString *quot = new_String();
+    iConstForEach(String, i, d) {
+        const iChar ch = i.value;
+        if (ch == '"') {
+            appendCStr_String(quot, "\\\"");
+        }
+        else if (ch == '\\') {
+            appendCStr_String(quot, "\\\\");
+        }
+        else if (ch == '\n') {
+            appendCStr_String(quot, "\\n");
+        }
+        else if (ch == '\r') {
+            appendCStr_String(quot, "\\r");
+        }
+        else if (ch == '\t') {
+            appendCStr_String(quot, "\\t");
+        }
+        else if (ch >= 0x100) {
+            appendFormat_String(quot, "\\u%04x", ch);
+        }
+        else {
+            appendChar_String(quot, ch);
+        }
+    }
+    return quot;
+}
+
+static iString *unquote_String_(const iString *d) {
+    iString *unquot = new_String();
+    iConstForEach(String, i, d) {
+        const iChar ch = i.value;
+        if (ch == '\\') {
+            next_StringConstIterator(&i);
+            const iChar esc = i.value;
+            if (esc == '\\') {
+                appendChar_String(unquot, esc);
+            }
+            else if (esc == 'n') {
+                appendChar_String(unquot, '\n');
+            }
+            else if (esc == 'r') {
+                appendChar_String(unquot, '\r');
+            }
+            else if (esc == 't') {
+                appendChar_String(unquot, '\t');
+            }
+            else if (esc == '"') {
+                appendChar_String(unquot, '"');
+            }
+            else if (esc == 'u') {
+                char digits[5];
+                iZap(digits);
+                iForIndices(j, digits) {
+                    next_StringConstIterator(&i);
+                    digits[j] = *i.pos;
+                }
+                iChar codepoint = strtoul(digits, NULL, 16);
+                if (codepoint) {
+                    appendChar_String(unquot, codepoint);
+                }
+            }
+            else {
+                iAssert(0);
+            }
+        }
+        else {
+            appendChar_String(unquot, ch);
+        }
+    }
+    return unquot;
+}
+
+static void finished_Translation_(iTlsRequest *d, iTlsRequest *req) {
+    iUnused(req);
+    postCommandf_App("translation.finished ptr:%p", userData_Object(d));
+}
+
+void init_Translation(iTranslation *d, iDocumentWidget *doc) {
+    d->dlg       = makeTranslation_Widget(as_Widget(doc));
+    d->startTime = 0;
+    d->doc       = doc; /* owner */
+    d->request   = new_TlsRequest();
+    d->timer     = 0;
+    setUserData_Object(d->request, d->doc);
+    setHost_TlsRequest(d->request,
+                       collectNewCStr_String(translationServiceHost),
+                       translationServicePort);
+    iConnect(TlsRequest, d->request, finished, d->request, finished_Translation_);
+}
+
+void deinit_Translation(iTranslation *d) {
+    if (d->timer) {
+        SDL_RemoveTimer(d->timer);
+    }
+    cancel_TlsRequest(d->request);
+    iRelease(d->request);
+    destroy_Widget(d->dlg);
+}
+
+static uint32_t animate_Translation_(uint32_t interval, iAny *ptr) {
+    postCommandf_App("translation.update ptr:%p", ((iTranslation *) ptr)->doc);
+    return interval;
+}
+
+void submit_Translation(iTranslation *d) {
+    /* Check the selected languages from the dialog. */
+    const char *idFrom = languageId_String(text_LabelWidget(findChild_Widget(d->dlg, "xlt.from")));
+    const char *idTo   = languageId_String(text_LabelWidget(findChild_Widget(d->dlg, "xlt.to")));
+    iAssert(status_TlsRequest(d->request) != submitted_TlsRequestStatus);
+    iBlock *json = collect_Block(new_Block(0));
+    iString *docSrc = collect_String(copy_String(source_GmDocument(document_DocumentWidget(d->doc))));
+    replace_String(docSrc, "=>", doubleArrowSymbol);
+    replace_String(docSrc, "```", tripleBacktickSymbol);
+    replace_String(docSrc, "###", h3Symbol);
+    replace_String(docSrc, "##", h2Symbol);
+    replace_String(docSrc, "#", h1Symbol);
+    printf_Block(json,
+                 "{\"q\":\"%s\",\"source\":\"%s\",\"target\":\"%s\"}",
+                 cstrCollect_String(quote_String_(docSrc)),
+                 idFrom,
+                 idTo);
+    iBlock *msg = collect_Block(new_Block(0));
+    printf_Block(msg, "POST /translate HTTP/1.1\r\n"
+                      "Host: xlt.skyjake.fi\r\n"
+                      "Connection: close\r\n"
+                      "Content-Type: application/json\r\n"
+                      "Content-Length: %zu\r\n\r\n", size_Block(json));
+    append_Block(msg, json);
+    setContent_TlsRequest(d->request, msg);
+    submit_TlsRequest(d->request);
+    d->startTime = SDL_GetTicks();
+    d->timer = SDL_AddTimer(1000 / 30, animate_Translation_, d);
+}
+
+static void processResult_Translation_(iTranslation *d) {
+    SDL_RemoveTimer(d->timer);
+    d->timer = 0;
+    if (status_TlsRequest(d->request) == error_TlsRequestStatus) {
+        return;
+    }
+    iBlock *resultData = collect_Block(readAll_TlsRequest(d->request));
+    printf("result(%zu):\n%s\n", size_Block(resultData), cstr_Block(resultData));
+    fflush(stdout);
+    iRegExp *pattern = iClob(new_RegExp(".*translatedText\":\"(.*)\"\\}", caseSensitive_RegExpOption));
+    iRegExpMatch m;
+    init_RegExpMatch(&m);
+    if (matchRange_RegExp(pattern, range_Block(resultData), &m)) {
+        iString *translation = unquote_String_(collect_String(captured_RegExpMatch(&m, 1)));
+        replace_String(translation, tripleBacktickSymbol, "```");
+        replace_String(translation, doubleArrowSymbol, "=>");
+        replace_String(translation, h3Symbol, "###");
+        replace_String(translation, h2Symbol, "##");
+        replace_String(translation, h1Symbol, "#");
+        setSource_DocumentWidget(d->doc, translation);
+        postCommand_App("sidebar.update");
+        delete_String(translation);
+    }
+    else {
+        /* TODO: Report failure! */
+    }
+}
+
+static iLabelWidget *acceptButton_Translation_(const iTranslation *d) {
+    return (iLabelWidget *) lastChild_Widget(findChild_Widget(d->dlg, "dialogbuttons"));
+}
+
+iBool handleCommand_Translation(iTranslation *d, const char *cmd) {
+    iWidget *w = as_Widget(d->doc);
+    if (equalWidget_Command(cmd, w, "translation.submit")) {
+        if (status_TlsRequest(d->request) == initialized_TlsRequestStatus) {
+            iWidget *langs = findChild_Widget(d->dlg, "xlt.langs");
+            setFlags_Widget(langs, hidden_WidgetFlag, iTrue);
+            iLabelWidget *acceptButton = acceptButton_Translation_(d);
+            updateTextCStr_LabelWidget(acceptButton, "00:00");
+            setFlags_Widget(as_Widget(acceptButton), disabled_WidgetFlag, iTrue);
+            iTranslationProgressWidget *prog = new_TranslationProgressWidget();
+            setPos_Widget(as_Widget(prog), langs->rect.pos);
+            setSize_Widget(as_Widget(prog), langs->rect.size);
+            addChild_Widget(d->dlg, iClob(prog));
+            submit_Translation(d);
+        }
+        return iTrue;
+    }
+    if (equalWidget_Command(cmd, w, "translation.update")) {
+        const uint32_t elapsed = SDL_GetTicks() - d->startTime;
+        const unsigned seconds = (elapsed / 1000) % 60;
+        const unsigned minutes = (elapsed / 60000);
+        updateText_LabelWidget(acceptButton_Translation_(d),
+                               collectNewFormat_String("%02u:%02u", minutes, seconds));
+        return iTrue;
+    }
+    if (equalWidget_Command(cmd, w, "translation.finished")) {
+        if (!isFinished_Translation(d)) {
+            processResult_Translation_(d);
+            destroy_Widget(d->dlg);
+            d->dlg = NULL;
+        }
+        return iTrue;
+    }
+    if (equalWidget_Command(cmd, d->dlg, "translation.cancel")) {
+        cancel_TlsRequest(d->request);
+        return iTrue;
+    }
+    return iFalse;
+}
+
+iBool isFinished_Translation(const iTranslation *d) {
+    return d->dlg == NULL;
+}
diff --git a/src/ui/translation.h b/src/ui/translation.h
new file mode 100644
index 00000000..6966e468
--- /dev/null
+++ b/src/ui/translation.h
@@ -0,0 +1,45 @@
+/* Copyright 2021 Jaakko Keränen <jaakko.keranen@iki.fi>
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
+
+#pragma once
+
+#include <the_Foundation/string.h>
+#include <the_Foundation/tlsrequest.h>
+
+iDeclareType(Translation)
+iDeclareType(DocumentWidget)
+iDeclareType(Widget)
+
+struct Impl_Translation {
+    iTlsRequest *    request;
+    iWidget *        dlg;
+    uint32_t         startTime;
+    iDocumentWidget *doc;
+    int              timer;
+};
+
+iDeclareTypeConstructionArgs(Translation, iDocumentWidget *)
+
+void    submit_Translation          (iTranslation *);
+iBool   handleCommand_Translation   (iTranslation *, const char *cmd);
+
+iBool   isFinished_Translation      (const iTranslation *);
diff --git a/src/ui/util.c b/src/ui/util.c
index a2aaa893..61ecf948 100644
--- a/src/ui/util.c
+++ b/src/ui/util.c
@@ -1688,8 +1688,19 @@ static void appendFramelessTabPage_(iWidget *tabs, iWidget *page, const char *ti
         iTrue);
 }
 
+static iWidget *makeTwoColumnWidget_(iWidget **headings, iWidget **values) {
+    iWidget *page = new_Widget();
+    setFlags_Widget(page, arrangeHorizontal_WidgetFlag | arrangeSize_WidgetFlag, iTrue);
+    *headings = addChildFlags_Widget(
+        page, iClob(new_Widget()), arrangeVertical_WidgetFlag | arrangeSize_WidgetFlag);
+    *values = addChildFlags_Widget(
+        page, iClob(new_Widget()), arrangeVertical_WidgetFlag | arrangeSize_WidgetFlag);
+    return page;
+}
+
 static iWidget *appendTwoColumnPage_(iWidget *tabs, const char *title, int shortcut, iWidget **headings,
                                      iWidget **values) {
+    /* TODO: Use `makeTwoColumnWidget_()`, see above. */
     iWidget *page = new_Widget();
     setFlags_Widget(page, arrangeVertical_WidgetFlag | arrangeSize_WidgetFlag |
                     resizeHeightOfChildren_WidgetFlag | borderTop_WidgetFlag, iTrue);
@@ -1935,13 +1946,8 @@ iWidget *makeBookmarkEditor_Widget(void) {
                      iClob(new_LabelWidget(uiHeading_ColorEscape "EDIT BOOKMARK", NULL)),
                      frameless_WidgetFlag),
                  "bmed.heading");
-    iWidget *page = new_Widget();
-    addChild_Widget(dlg, iClob(page));
-    setFlags_Widget(page, arrangeHorizontal_WidgetFlag | arrangeSize_WidgetFlag, iTrue);
-    iWidget *headings = addChildFlags_Widget(
-        page, iClob(new_Widget()), arrangeVertical_WidgetFlag | arrangeSize_WidgetFlag);
-    iWidget *values = addChildFlags_Widget(
-        page, iClob(new_Widget()), arrangeVertical_WidgetFlag | arrangeSize_WidgetFlag);
+    iWidget *headings, *values;
+    addChild_Widget(dlg, iClob(makeTwoColumnWidget_(&headings, &values)));
     iInputWidget *inputs[4];
     addChild_Widget(headings, iClob(makeHeading_Widget("Title:")));
     setId_Widget(addChild_Widget(values, iClob(inputs[0] = new_InputWidget(0))), "bmed.title");
@@ -2074,13 +2080,8 @@ iWidget *makeFeedSettings_Widget(uint32_t bookmarkId) {
                                            NULL)),
                      frameless_WidgetFlag),
                  "feedcfg.heading");
-    iWidget *page = new_Widget();
-    addChild_Widget(dlg, iClob(page));
-    setFlags_Widget(page, arrangeHorizontal_WidgetFlag | arrangeSize_WidgetFlag, iTrue);
-    iWidget *headings = addChildFlags_Widget(
-        page, iClob(new_Widget()), arrangeVertical_WidgetFlag | arrangeSize_WidgetFlag);
-    iWidget *values = addChildFlags_Widget(
-        page, iClob(new_Widget()), arrangeVertical_WidgetFlag | arrangeSize_WidgetFlag);
+    iWidget *headings, *values;
+    addChild_Widget(dlg, iClob(makeTwoColumnWidget_(&headings, &values)));
     addChild_Widget(headings, iClob(makeHeading_Widget("Title:")));
     iInputWidget *input = new_InputWidget(0);
     setId_Widget(addChild_Widget(values, iClob(input)), "feedcfg.title");
@@ -2184,3 +2185,81 @@ iWidget *makeIdentityCreation_Widget(void) {
     finalizeSheet_Widget(dlg);
     return dlg;
 }
+
+static const iMenuItem languages[] = {
+    { "Arabic", 0, 0, "xlt.lang id:ar" },
+    { "Chinese", 0, 0, "xlt.lang id:zh" },
+    { "English", 0, 0, "xlt.lang id:en" },
+    { "French", 0, 0, "xlt.lang id:fr" },
+    { "German", 0, 0, "xlt.lang id:de" },
+    { "Hindi", 0, 0, "xlt.lang id:hi" },
+    { "Italian", 0, 0, "xlt.lang id:it" },
+    { "Japanese", 0, 0, "xlt.lang id:ja" },
+    { "Portuguese", 0, 0, "xlt.lang id:pt" },
+    { "Russian", 0, 0, "xlt.lang id:ru" },
+    { "Spanish", 0, 0, "xlt.lang id:es" },
+};
+
+static iBool translationHandler_(iWidget *dlg, const char *cmd) {
+    if (equal_Command(cmd, "xlt.lang")) {
+        iLabelWidget *menuItem = pointer_Command(cmd);
+        iWidget *button = parent_Widget(parent_Widget(menuItem));
+        iAssert(isInstance_Object(button, &Class_LabelWidget));
+        updateText_LabelWidget((iLabelWidget *) button, text_LabelWidget(menuItem));
+        return iTrue;
+    }
+    return iFalse;
+}
+
+const char *languageId_String(const iString *menuItemLabel) {
+    iForIndices(i, languages) {
+        if (!cmp_String(menuItemLabel, languages[i].label)) {
+            return cstr_Rangecc(range_Command(languages[i].command, "id"));
+        }
+    }
+    return "";
+}
+
+iWidget *makeTranslation_Widget(iWidget *parent) {
+    iWidget *dlg = makeSheet_Widget("xlt");
+    setCommandHandler_Widget(dlg, translationHandler_);
+    addChildFlags_Widget(dlg,
+                         iClob(new_LabelWidget(uiHeading_ColorEscape "TRANSLATE PAGE", NULL)),
+                         frameless_WidgetFlag);
+    addChild_Widget(dlg, iClob(makePadding_Widget(lineHeight_Text(uiLabel_FontId))));
+    iWidget *headings, *values;
+    iWidget *page;
+    addChild_Widget(dlg, iClob(page = makeTwoColumnWidget_(&headings, &values)));
+    setId_Widget(page, "xlt.langs");
+    addChild_Widget(headings, iClob(makeHeading_Widget("From:")));
+    iLabelWidget *fromLang, *toLang;
+    setId_Widget(addChildFlags_Widget(values,
+                                      iClob(fromLang = makeMenuButton_LabelWidget(
+                                                "Portuguese", languages, iElemCount(languages))),
+                                      alignLeft_WidgetFlag),
+                 "xlt.from");
+    updateTextCStr_LabelWidget(fromLang, "French"); /* TODO: Check source media type; remember last use. */
+    setBackgroundColor_Widget(findChild_Widget(as_Widget(fromLang), "menu"),
+                              uiBackgroundMenu_ColorId);
+    addChild_Widget(headings, iClob(makeHeading_Widget("To:")));
+    setId_Widget(addChildFlags_Widget(values,
+                                      iClob(toLang = makeMenuButton_LabelWidget(
+                                                "Portuguese", languages, iElemCount(languages))),
+                                      alignLeft_WidgetFlag),
+                 "xlt.to");
+    setBackgroundColor_Widget(findChild_Widget(as_Widget(toLang), "menu"),
+                              uiBackgroundMenu_ColorId);
+    updateTextCStr_LabelWidget(toLang, "English"); /* TODO: User preference. */
+    addChild_Widget(dlg, iClob(makePadding_Widget(lineHeight_Text(uiLabel_FontId))));
+    addChild_Widget(
+        dlg,
+        iClob(makeDialogButtons_Widget(
+            (iMenuItem[]){
+                { "Cancel", SDLK_ESCAPE, 0, "translation.cancel" },
+                { uiTextAction_ColorEscape "Translate", SDLK_RETURN, 0, "translation.submit" } },
+            2)));
+    addChild_Widget(parent, iClob(dlg));
+    arrange_Widget(dlg);
+    finalizeSheet_Widget(dlg);
+    return dlg;
+}
diff --git a/src/ui/util.h b/src/ui/util.h
index e2461b9d..251683f5 100644
--- a/src/ui/util.h
+++ b/src/ui/util.h
@@ -223,3 +223,6 @@ iWidget *   makeBookmarkEditor_Widget   (void);
 iWidget *   makeBookmarkCreation_Widget (const iString *url, const iString *title, iChar icon);
 iWidget *   makeIdentityCreation_Widget (void);
 iWidget *   makeFeedSettings_Widget     (uint32_t bookmarkId);
+iWidget *   makeTranslation_Widget      (iWidget *parent);
+
+const char *    languageId_String   (const iString *menuItemLabel);