DocumentWidget: Smooth scrolling for keyboard

4 files changed, 112 insertions, 12 deletions

diff --git a/src/app.c b/src/app.c
index 76298ec5..1e37030f 100644
--- a/src/app.c
+++ b/src/app.c
@@ -47,6 +47,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
 #include <the_Foundation/time.h>
 #include <SDL_events.h>
 #include <SDL_render.h>
+#include <SDL_timer.h>
 #include <SDL_video.h>
 
 #include <stdio.h>
@@ -82,6 +83,8 @@ struct Impl_App {
     iBookmarks * bookmarks;
     iWindow *    window;
     iSortedArray tickers;
+    uint32_t     lastTickerTime;
+    uint32_t     elapsedSinceLastTicker;
     iBool        running;
     iBool        pendingRefresh;
     int          tabEnum;
@@ -255,6 +258,8 @@ static void saveState_App_(const iApp *d) {
 static void init_App_(iApp *d, int argc, char **argv) {
     init_CommandLine(&d->args, argc, argv);
     init_SortedArray(&d->tickers, sizeof(iTicker), cmp_Ticker_);
+    d->lastTickerTime    = SDL_GetTicks();
+    d->elapsedSinceLastTicker = 0;
     d->commandEcho       = checkArgument_CommandLine(&d->args, "echo") != NULL;
     d->initialWindowRect = init_Rect(-1, -1, 800, 500);
     d->theme             = dark_ColorTheme;
@@ -350,6 +355,9 @@ backToMainLoop:;
 }
 
 static void runTickers_App_(iApp *d) {
+    const uint32_t now = SDL_GetTicks();
+    d->elapsedSinceLastTicker = (d->lastTickerTime ? now - d->lastTickerTime : 0);
+    d->lastTickerTime = now;
     /* Tickers may add themselves again, so we'll run off a copy. */
     iSortedArray *pending = copy_SortedArray(&d->tickers);
     clear_SortedArray(&d->tickers);
@@ -389,6 +397,10 @@ iBool isRefreshPending_App(void) {
     return app_.pendingRefresh;
 }
 
+uint32_t elapsedSinceLastTicker_App(void) {
+    return app_.elapsedSinceLastTicker;
+}
+
 int zoom_App(void) {
     return app_.zoomPercent;
 }
@@ -407,6 +419,9 @@ int run_App(int argc, char **argv) {
 void postRefresh_App(void) {
     iApp *d = &app_;
     if (!d->pendingRefresh) {
+        if (!isEmpty_SortedArray(&d->tickers)) {
+            d->lastTickerTime = 0; /* tickers had been paused */
+        }
         d->pendingRefresh = iTrue;
         SDL_Event ev;
         ev.user.type     = SDL_USEREVENT;
@@ -454,6 +469,7 @@ iAny *findWidget_App(const char *id) {
 void addTicker_App(void (*ticker)(iAny *), iAny *context) {
     iApp *d = &app_;
     insert_SortedArray(&d->tickers, &(iTicker){ context, ticker });
+    postRefresh_App();
 }
 
 iGmCerts *certs_App(void) {
diff --git a/src/app.h b/src/app.h
index 75fc4331..1a6b7fe5 100644
--- a/src/app.h
+++ b/src/app.h
@@ -48,11 +48,12 @@ enum iUserEventCode {
 const iString *execPath_App     (void);
 const iString *dataDir_App      (void);
 
-int         run_App             (int argc, char **argv);
-void        processEvents_App   (enum iAppEventMode mode);
-iBool       handleCommand_App   (const char *cmd);
-void        refresh_App         (void);
-iBool       isRefreshPending_App(void);
+int         run_App                     (int argc, char **argv);
+void        processEvents_App           (enum iAppEventMode mode);
+iBool       handleCommand_App           (const char *cmd);
+void        refresh_App                 (void);
+iBool       isRefreshPending_App        (void);
+uint32_t    elapsedSinceLastTicker_App  (void); /* milliseconds */
 
 int                 zoom_App            (void);
 enum iColorTheme    colorTheme_App      (void);
diff --git a/src/ui/color.c b/src/ui/color.c
index dcdc5788..441db18d 100644
--- a/src/ui/color.c
+++ b/src/ui/color.c
@@ -187,7 +187,7 @@ void setThemePalette_Color(enum iColorTheme theme) {
             copy_(uiInputBackgroundFocused_ColorId, white_ColorId);
             copy_(uiInputText_ColorId, gray25_ColorId);
             copy_(uiInputTextFocused_ColorId, black_ColorId);
-            copy_(uiInputFrame_ColorId, gray25_ColorId);
+            copy_(uiInputFrame_ColorId, gray50_ColorId);
             copy_(uiInputFrameHover_ColorId, brown_ColorId);
             copy_(uiInputFrameFocused_ColorId, teal_ColorId);
             copy_(uiInputCursor_ColorId, teal_ColorId);
diff --git a/src/ui/documentwidget.c b/src/ui/documentwidget.c
index a36fe761..5292d3f5 100644
--- a/src/ui/documentwidget.c
+++ b/src/ui/documentwidget.c
@@ -162,6 +162,8 @@ iDefineTypeConstruction(VisBuffer)
 
 /*----------------------------------------------------------------------------------------------*/
 
+static const int smoothSpeed_DocumentWidget_ = 150; /* unit: gap_Text per second */
+
 enum iRequestState {
     blank_RequestState,
     fetching_RequestState,
@@ -193,6 +195,10 @@ struct Impl_DocumentWidget {
     iClick         click;
     float          initNormScrollY;
     int            scrollY;
+    int            smoothScroll;
+    int            smoothSpeed;
+    int            lastSmoothOffset;
+    iBool          keepScrolling;
     iScrollWidget *scroll;
     iWidget *      menu;
     iVisBuffer *   visBuffer;
@@ -217,6 +223,10 @@ void init_DocumentWidget(iDocumentWidget *d) {
     d->doc              = new_GmDocument();
     d->initNormScrollY  = 0;
     d->scrollY          = 0;
+    d->smoothScroll     = 0;
+    d->smoothSpeed      = 0;
+    d->lastSmoothOffset = 0;
+    d->keepScrolling    = iFalse;
     d->selecting        = iFalse;
     d->selectMark       = iNullRange;
     d->foundMark        = iNullRange;
@@ -254,6 +264,13 @@ void deinit_DocumentWidget(iDocumentWidget *d) {
     deinit_Model(&d->mod);
 }
 
+static void resetSmoothScroll_DocumentWidget_(iDocumentWidget *d) {
+    d->smoothSpeed      = 0;
+    d->smoothScroll     = 0;
+    d->lastSmoothOffset = 0;
+    d->keepScrolling    = iFalse;
+}
+
 static int documentWidth_DocumentWidget_(const iDocumentWidget *d) {
     const iWidget *w = constAs_Widget(d);
     const iRect bounds = bounds_Widget(w);
@@ -287,9 +304,11 @@ iLocalDef int documentToWindowY_DocumentWidget_(const iDocumentWidget *d, int do
     return docY - d->scrollY + documentBounds_DocumentWidget_(d).pos.y;
 }
 
+#if 0
 iLocalDef int windowToDocumentY_DocumentWidget_(const iDocumentWidget *d, int localY) {
     return localY + d->scrollY - documentBounds_DocumentWidget_(d).pos.y;
 }
+#endif
 
 static iInt2 documentPos_DocumentWidget_(const iDocumentWidget *d, iInt2 pos) {
     return addY_I2(sub_I2(pos, topLeft_Rect(documentBounds_DocumentWidget_(d))), d->scrollY);
@@ -500,6 +519,7 @@ static void showErrorPage_DocumentWidget_(iDocumentWidget *d, enum iGmStatusCode
             break;
     }
     setSource_DocumentWidget_(d, src);
+    resetSmoothScroll_DocumentWidget_(d);
     d->scrollY = 0;
     d->state = ready_RequestState;
 }
@@ -743,6 +763,37 @@ static void scroll_DocumentWidget_(iDocumentWidget *d, int offset) {
     refresh_Widget(as_Widget(d));
 }
 
+static void doScroll_DocumentWidget_(iAny *ptr) {
+    iDocumentWidget *d = ptr;
+    if (!d->smoothScroll) return; /* was cancelled */
+    const double elapsed = (double) elapsedSinceLastTicker_App() / 1000.0;
+    int delta = d->smoothSpeed * elapsed * iSign(d->smoothScroll);
+    if (iAbs(d->smoothScroll) <= iAbs(delta)) {
+        if (d->keepScrolling) {
+            d->smoothScroll += d->lastSmoothOffset;
+        }
+        else {
+            delta = d->smoothScroll;
+        }
+    }
+    scroll_DocumentWidget_(d, delta);
+    d->smoothScroll -= delta;
+    if (d->smoothScroll != 0) {
+        addTicker_App(doScroll_DocumentWidget_, d);
+    }
+}
+
+static void smoothScroll_DocumentWidget_(iDocumentWidget *d, int offset, int speed) {
+    if (speed == 0) {
+        scroll_DocumentWidget_(d, offset);
+        return;
+    }
+    d->smoothSpeed = speed;
+    d->smoothScroll += offset;
+    d->lastSmoothOffset = offset;
+    addTicker_App(doScroll_DocumentWidget_, d);
+}
+
 static void scrollTo_DocumentWidget_(iDocumentWidget *d, int documentY, iBool centered) {
     d->scrollY = documentY - (centered ? documentBounds_DocumentWidget_(d).size.y / 2 :
                                        lineHeight_Text(paragraph_FontId));
@@ -780,6 +831,7 @@ static void checkResponse_DocumentWidget_(iDocumentWidget *d) {
             }
             case categorySuccess_GmStatusCode:
                 d->scrollY = 0;
+                resetSmoothScroll_DocumentWidget_(d);
                 reset_GmDocument(d->doc); /* new content incoming */
                 updateDocument_DocumentWidget_(d, response_GmRequest(d->request));
                 break;
@@ -1076,6 +1128,7 @@ static iBool handleCommand_DocumentWidget_(iDocumentWidget *d, const char *cmd)
     else if (equalWidget_Command(cmd, w, "document.request.finished") &&
              pointerLabel_Command(cmd, "request") == d->request) {
         checkResponse_DocumentWidget_(d);
+        resetSmoothScroll_DocumentWidget_(d);
         d->scrollY = d->initNormScrollY * size_GmDocument(d->doc).y;
         d->state = ready_RequestState;
         /* The response may be cached. */ {
@@ -1123,12 +1176,24 @@ static iBool handleCommand_DocumentWidget_(iDocumentWidget *d, const char *cmd)
     }
     else if (equalWidget_Command(cmd, w, "scroll.moved")) {
         d->scrollY = arg_Command(cmd);
+        resetSmoothScroll_DocumentWidget_(d);
         updateVisible_DocumentWidget_(d);
         return iTrue;
     }
     else if (equalWidget_Command(cmd, w, "scroll.page")) {
-        scroll_DocumentWidget_(d,
-                               arg_Command(cmd) * height_Rect(documentBounds_DocumentWidget_(d)));
+        if (argLabel_Command(cmd, "repeat")) {
+            if (!d->keepScrolling) {
+                d->keepScrolling = iTrue;
+            }
+            else {
+                return iTrue;
+            }
+        }
+        smoothScroll_DocumentWidget_(d,
+                                     arg_Command(cmd) *
+                                         (0.5f * height_Rect(documentBounds_DocumentWidget_(d)) -
+                                          0 * lineHeight_Text(paragraph_FontId)),
+                                     15 * smoothSpeed_DocumentWidget_);
         return iTrue;
     }
     else if (equal_Command(cmd, "document.goto") && document_App() == d) {
@@ -1211,6 +1276,13 @@ static iBool processEvent_DocumentWidget_(iDocumentWidget *d, const SDL_Event *e
                     refresh_Widget(w);
                 }
                 break;
+            case SDLK_PAGEUP:
+            case SDLK_PAGEDOWN:
+            case SDLK_SPACE:
+            case SDLK_UP:
+            case SDLK_DOWN:
+                d->keepScrolling = iFalse;
+                break;
         }
     }
     if (ev->type == SDL_KEYDOWN) {
@@ -1241,12 +1313,14 @@ static iBool processEvent_DocumentWidget_(iDocumentWidget *d, const SDL_Event *e
                 break;
             case SDLK_HOME:
                 d->scrollY = 0;
+                resetSmoothScroll_DocumentWidget_(d);
                 scroll_DocumentWidget_(d, 0);
                 updateVisible_DocumentWidget_(d);
                 refresh_Widget(w);
                 return iTrue;
             case SDLK_END:
                 d->scrollY = scrollMax_DocumentWidget_(d);
+                resetSmoothScroll_DocumentWidget_(d);
                 scroll_DocumentWidget_(d, 0);
                 updateVisible_DocumentWidget_(d);
                 refresh_Widget(w);
@@ -1254,8 +1328,16 @@ static iBool processEvent_DocumentWidget_(iDocumentWidget *d, const SDL_Event *e
             case SDLK_UP:
             case SDLK_DOWN:
                 if (mods == 0) {
-                    scroll_DocumentWidget_(d, 2 * lineHeight_Text(default_FontId) *
-                                                  (key == SDLK_UP ? -1 : 1));
+                    if (ev->key.repeat) {
+                        if (!d->keepScrolling) {
+                            d->keepScrolling = iTrue;
+                        }
+                        else return iTrue;
+                    }
+                    smoothScroll_DocumentWidget_(d,
+                                                 3 * lineHeight_Text(paragraph_FontId) *
+                                                     (key == SDLK_UP ? -1 : 1),
+                                                 gap_Text * smoothSpeed_DocumentWidget_);
                     return iTrue;
                 }
                 break;
@@ -1264,8 +1346,9 @@ static iBool processEvent_DocumentWidget_(iDocumentWidget *d, const SDL_Event *e
             case SDLK_SPACE:
                 postCommand_Widget(
                     w,
-                    "scroll.page arg:%d",
-                    (key == SDLK_SPACE && mods & KMOD_SHIFT) || key == SDLK_PAGEUP ? -1 : +1);
+                    "scroll.page arg:%d repeat:%d",
+                    (key == SDLK_SPACE && mods & KMOD_SHIFT) || key == SDLK_PAGEUP ? -1 : +1,
+                    ev->key.repeat != 0);
                 return iTrue;
 #if 1
             case SDLK_KP_1: {