Scrollbar fading and periodic commands

Added a new mechanism to issue periodic but not per-frame commands. This is used for main-thread operations like checking if it's time to fade away the scrollbars.

Scrollbars are faded away completely on Apple platforms. Adjusted list right margins accordingly.

8 files changed, 128 insertions, 34 deletions

diff --git a/src/ui/listwidget.c b/src/ui/listwidget.c
index 237562ca..f351c3b3 100644
--- a/src/ui/listwidget.c
+++ b/src/ui/listwidget.c
@@ -379,9 +379,13 @@ static void draw_ListWidget_(const iListWidget *d) {
                 beginTarget_Paint(&p, buf->texture);
                 fillRect_Paint(&p, (iRect){ zero_I2(), d->visBuf->texSize }, bg[i]);
             }
-            const iRect sbBlankRect =
-                { init_I2(d->visBuf->texSize.x - scrollBarWidth_ListWidget(d), 0),
-                         init_I2(scrollBarWidth_ListWidget(d), d->itemHeight) };
+#if defined (iPlatformApple)
+            const int blankWidth = 0; /* scrollbars fade away */
+#else
+            const int blankWidth = scrollBarWidth_ListWidget(d);
+#endif
+            const iRect sbBlankRect = { init_I2(d->visBuf->texSize.x - blankWidth, 0),
+                                        init_I2(blankWidth, d->itemHeight) };
             iConstForEach(IntSet, v, &d->invalidItems) {
                 const size_t index = *v.value;
                 if (contains_Range(&drawItems, index)) {
diff --git a/src/ui/scrollwidget.c b/src/ui/scrollwidget.c
index e887ddbf..a08b58d7 100644
--- a/src/ui/scrollwidget.c
+++ b/src/ui/scrollwidget.c
@@ -23,9 +23,23 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
 #include "scrollwidget.h"
 #include "paint.h"
 #include "util.h"
+#include "periodic.h"
+#include "app.h"
+
+#include <SDL_timer.h>
 
 iDefineObjectConstruction(ScrollWidget)
 
+static float minOpacity_(void) {
+#if !defined (iPlatformApple)
+    if (deviceType_App() == desktop_AppDeviceType) {
+        /* Don't fade the scrollbars completely. */
+        return 0.333f;
+    }
+#endif
+    return 0.0f;
+}
+
 struct Impl_ScrollWidget {
     iWidget widget;
     iRangei range;
@@ -33,12 +47,23 @@ struct Impl_ScrollWidget {
     int thumbSize;
     iClick click;
     int startThumb;
+    iAnim opacity;
+    uint32_t fadeStart;
+    iBool willCheckFade;
 };
 
 static void updateMetrics_ScrollWidget_(iScrollWidget *d) {
     as_Widget(d)->rect.size.x = gap_UI * 3;
 }
 
+static void animateOpacity_ScrollWidget_(void *ptr) {
+    iScrollWidget *d = ptr;
+    if (!isFinished_Anim(&d->opacity)) {
+        addTicker_App(animateOpacity_ScrollWidget_, ptr);
+    }
+    refresh_Widget(ptr);
+}
+
 void init_ScrollWidget(iScrollWidget *d) {
     iWidget *w = as_Widget(d);
     init_Widget(w);
@@ -49,10 +74,13 @@ void init_ScrollWidget(iScrollWidget *d) {
                     iTrue);
     updateMetrics_ScrollWidget_(d);
     init_Click(&d->click, d, SDL_BUTTON_LEFT);
+    init_Anim(&d->opacity, minOpacity_());
+    d->willCheckFade = iFalse;
 }
 
 void deinit_ScrollWidget(iScrollWidget *d) {
-    iUnused(d);
+    remove_Periodic(periodic_App(), d);
+    removeTicker_App(animateOpacity_ScrollWidget_, d);
 }
 
 static int thumbSize_ScrollWidget_(const iScrollWidget *d) {
@@ -74,10 +102,26 @@ static iRect thumbRect_ScrollWidget_(const iScrollWidget *d) {
     return rect;
 }
 
+static void unfade_ScrollWidget_(iScrollWidget *d, float opacity) {
+    d->fadeStart = SDL_GetTicks() + 1000;
+    if (targetValue_Anim(&d->opacity) < opacity) {
+        setValue_Anim(&d->opacity, opacity, 66);
+        addTicker_App(animateOpacity_ScrollWidget_, d);
+    }
+    if (!d->willCheckFade) {
+        d->willCheckFade = iTrue;
+        add_Periodic(periodic_App(), d, "scrollbar.fade");
+    }
+    refresh_Widget(d);
+}
+
 static void checkVisible_ScrollWidget_(iScrollWidget *d) {
-    setFlags_Widget(as_Widget(d),
-                    hidden_WidgetFlag,
-                    d->thumbSize != 0 ? height_Rect(thumbRect_ScrollWidget_(d)) == 0 : iTrue);
+    const iBool wasHidden = isVisible_Widget(d);
+    const iBool isHidden = d->thumbSize != 0 ? height_Rect(thumbRect_ScrollWidget_(d)) == 0 : iTrue;
+    setFlags_Widget(as_Widget(d), hidden_WidgetFlag, isHidden);
+    if (wasHidden && !isHidden) {
+        unfade_ScrollWidget_(d, 1.0f);
+    }
 }
 
 void setRange_ScrollWidget(iScrollWidget *d, iRangei range) {
@@ -87,9 +131,13 @@ void setRange_ScrollWidget(iScrollWidget *d, iRangei range) {
 }
 
 void setThumb_ScrollWidget(iScrollWidget *d, int thumb, int thumbSize) {
+    const int oldThumb = d->thumb;
     d->thumb     = thumb;
     d->thumbSize = thumbSize;
     checkVisible_ScrollWidget_(d);
+    if (oldThumb != d->thumb && thumbSize) {
+        unfade_ScrollWidget_(d, 1.0f);
+    }
 }
 
 static iBool processEvent_ScrollWidget_(iScrollWidget *d, const SDL_Event *ev) {
@@ -97,6 +145,25 @@ static iBool processEvent_ScrollWidget_(iScrollWidget *d, const SDL_Event *ev) {
     if (isMetricsChange_UserEvent(ev)) {
         updateMetrics_ScrollWidget_(d);
     }
+    if (ev->type == SDL_MOUSEMOTION) {
+        const iInt2 mouse = init_I2(ev->motion.x, ev->motion.y);
+        const iBool isNearby = containsExpanded_Widget(&d->widget, mouse, 4 * gap_UI);
+        const iBool isOver = isNearby && contains_Rect(thumbRect_ScrollWidget_(d), mouse);
+        if (isNearby) {
+            unfade_ScrollWidget_(d, isOver ? 1.0f : 0.4f);
+        }
+    }
+    if (isCommand_UserEvent(ev, "scrollbar.fade")) {
+        if (d->willCheckFade && SDL_GetTicks() > d->fadeStart) {
+            setValue_Anim(&d->opacity, minOpacity_(), 200);
+            remove_Periodic(periodic_App(), d);
+            d->willCheckFade = iFalse;
+            if (!isFinished_Anim(&d->opacity)) {
+                addTicker_App(animateOpacity_ScrollWidget_, d);
+            }
+        }
+        return iFalse;
+    }
     switch (processEvent_Click(&d->click, ev)) {
         case started_ClickResult:
             setFlags_Widget(w, pressed_WidgetFlag, iTrue);
@@ -146,10 +213,18 @@ static void draw_ScrollWidget_(const iScrollWidget *d) {
     if (bounds.size.x > 0) {
         iPaint p;
         init_Paint(&p);
-        //drawVLine_Paint(&p, topLeft_Rect(bounds), height_Rect(bounds), uiSeparator_ColorId);
+        /* Blend if opacity is not at maximum. */
+        p.alpha = 255 * value_Anim(&d->opacity);
+        SDL_Renderer *render = renderer_Window(get_Window());
+        if (p.alpha < 255) {
+            SDL_SetRenderDrawBlendMode(render, SDL_BLENDMODE_BLEND);
+        }
         const iRect thumbRect = shrunk_Rect(
             thumbRect_ScrollWidget_(d), init_I2(isPressed ? gap_UI : (gap_UI * 4 / 3), gap_UI / 2));
         fillRect_Paint(&p, thumbRect, isPressed ? uiBackgroundPressed_ColorId : tmQuote_ColorId);
+        if (p.alpha < 255) {
+            SDL_SetRenderDrawBlendMode(render, SDL_BLENDMODE_NONE);
+        }
     }
 }
 
diff --git a/src/ui/sidebarwidget.c b/src/ui/sidebarwidget.c
index 802669c7..ac119575 100644
--- a/src/ui/sidebarwidget.c
+++ b/src/ui/sidebarwidget.c
@@ -143,7 +143,7 @@ static void updateItems_SidebarWidget_(iSidebarWidget *d) {
             iDate on;
             initCurrent_Time(&now);
             init_Date(&on, &now);
-            const int thisYear = on.year;
+            const iDate today = on;
             iZap(on);
             size_t numItems = 0;
             iConstForEach(PtrArray, i, listEntries_Feeds()) {
@@ -1306,6 +1306,11 @@ static void draw_SidebarItem_(const iSidebarItem *d, iPaint *p, iRect itemRect,
     const iBool isHover      = isHover_Widget(constAs_Widget(list)) &&
                                constHoverItem_ListWidget(list) == d;
     const int scrollBarWidth = scrollBarWidth_ListWidget(list);
+#if defined (iPlatformApple)
+    const int blankWidth     = 0;
+#else
+    const int blankWidth     = scrollBarWidth;
+#endif
     const int itemHeight     = height_Rect(itemRect);
     const int iconColor      = isHover ? (isPressing ? uiTextPressed_ColorId : uiIconHover_ColorId)
                                        : uiIcon_ColorId;
@@ -1345,7 +1350,7 @@ static void draw_SidebarItem_(const iSidebarItem *d, iPaint *p, iRect itemRect,
             if (d != constItem_ListWidget(list, 0)) {
                 drawHLine_Paint(p,
                                 addY_I2(pos, 2 * gap_UI),
-                                width_Rect(itemRect) - scrollBarWidth,
+                                width_Rect(itemRect) - blankWidth,
                                 uiSeparator_ColorId);
             }
             drawRange_Text(
@@ -1463,7 +1468,7 @@ static void draw_SidebarItem_(const iSidebarItem *d, iPaint *p, iRect itemRect,
                 iInt2 drawPos = addY_I2(topLeft_Rect(itemRect), d->id);
                 drawHLine_Paint(p,
                                 addY_I2(drawPos, -gap_UI),
-                                width_Rect(itemRect) - scrollBarWidth,
+                                width_Rect(itemRect) - blankWidth,
                                 uiSeparator_ColorId);
                 drawRange_Text(
                     uiLabelLargeBold_FontId,
diff --git a/src/ui/util.c b/src/ui/util.c
index e07e036a..13d1bf78 100644
--- a/src/ui/util.c
+++ b/src/ui/util.c
@@ -401,6 +401,7 @@ static iBool isCommandIgnoredByMenus_(const char *cmd) {
            equal_Command(cmd, "document.request.updated") ||
            equal_Command(cmd, "document.request.finished") ||
            equal_Command(cmd, "document.changed") ||
+           equal_Command(cmd, "scrollbar.fade") ||
            equal_Command(cmd, "visited.changed") ||
            (deviceType_App() == desktop_AppDeviceType && equal_Command(cmd, "window.resized")) ||
            equal_Command(cmd, "widget.overflow") ||
@@ -1634,12 +1635,14 @@ void updateValueInput_Widget(iWidget *d, const char *title, const char *prompt)
 
 static iBool messageHandler_(iWidget *msg, const char *cmd) {
     /* Almost any command dismisses the sheet. */
+    /* TODO: Use a "notification" prefix (like `) to ignore all types of commands line this? */
     if (!(equal_Command(cmd, "media.updated") ||
           equal_Command(cmd, "media.player.update") ||
           equal_Command(cmd, "bookmarks.request.finished") ||
           equal_Command(cmd, "document.autoreload") ||
           equal_Command(cmd, "document.reload") ||
           equal_Command(cmd, "document.request.updated") ||
+          equal_Command(cmd, "scrollbar.fade") ||
           equal_Command(cmd, "widget.overflow") ||
           startsWith_CStr(cmd, "window."))) {
         destroy_Widget(msg);
diff --git a/src/ui/util.h b/src/ui/util.h
index 35e10c6f..09e52a4d 100644
--- a/src/ui/util.h
+++ b/src/ui/util.h
@@ -102,7 +102,6 @@ struct Impl_Anim {
 
 void    init_Anim           (iAnim *, float value);
 void    setValue_Anim       (iAnim *, float to, uint32_t span);
-void    setValueLinear_Anim (iAnim *, float to, uint32_t span);
 void    setValueEased_Anim  (iAnim *, float to, uint32_t span);
 void    setFlags_Anim       (iAnim *, int flags, iBool set);
 void    stop_Anim           (iAnim *);
diff --git a/src/ui/widget.c b/src/ui/widget.c
index d5e639fd..4f5d174c 100644
--- a/src/ui/widget.c
+++ b/src/ui/widget.c
@@ -582,10 +582,17 @@ iInt2 localCoord_Widget(const iWidget *d, iInt2 coord) {
 }
 
 iBool contains_Widget(const iWidget *d, iInt2 coord) {
-    const iRect bounds = { zero_I2(), addY_I2(d->rect.size,
-                                              d->flags & drawBackgroundToBottom_WidgetFlag ?
-                                                rootSize_Window(get_Window()).y : 0) };
-    return contains_Rect(bounds, localCoord_Widget(d, coord));
+    return containsExpanded_Widget(d, coord, 0);
+}
+
+iBool containsExpanded_Widget(const iWidget *d, iInt2 coord, int expand) {
+    const iRect bounds = {
+        zero_I2(),
+        addY_I2(d->rect.size,
+                d->flags & drawBackgroundToBottom_WidgetFlag ? rootSize_Window(get_Window()).y : 0)
+    };
+    return contains_Rect(expand ? expanded_Rect(bounds, init1_I2(expand)) : bounds,
+                         localCoord_Widget(d, coord));
 }
 
 iLocalDef iBool isKeyboardEvent_(const SDL_Event *ev) {
@@ -854,8 +861,8 @@ void drawBackground_Widget(const iWidget *d) {
         const iBool isLight = isLight_ColorTheme(colorTheme_App());
         p.alpha = isLight ? 0xc : 0x20;
         SDL_SetRenderDrawBlendMode(renderer_Window(get_Window()), SDL_BLENDMODE_BLEND);
-        iRect shadowRect = expanded_Rect(bounds_Widget(d), mulf_I2(gap2_UI, 1));
-        shadowRect.pos.y += gap_UI / 4;
+        iRect shadowRect = expanded_Rect(bounds_Widget(d), mulf_I2(gap2_UI, 8));
+//        shadowRect.pos.y += gap_UI * 4;
         fillRect_Paint(&p, shadowRect, /*isLight ? white_ColorId :*/ black_ColorId);
         SDL_SetRenderDrawBlendMode(renderer_Window(get_Window()), SDL_BLENDMODE_NONE);
     }
diff --git a/src/ui/widget.h b/src/ui/widget.h
index 88d75b62..90ccac8e 100644
--- a/src/ui/widget.h
+++ b/src/ui/widget.h
@@ -161,21 +161,22 @@ void    destroy_Widget          (iWidget *); /* widget removed and deleted later
 void    destroyPending_Widget   (void);
 void    releaseChildren_Widget  (iWidget *);
 
-const iString *id_Widget    (const iWidget *);
-int64_t flags_Widget        (const iWidget *);
-iRect   bounds_Widget       (const iWidget *); /* outer bounds */
-iRect   innerBounds_Widget  (const iWidget *);
-iInt2   localCoord_Widget   (const iWidget *, iInt2 coord);
-iBool   contains_Widget     (const iWidget *, iInt2 coord);
-iAny *  hitChild_Widget     (const iWidget *, iInt2 coord);
-iAny *  findChild_Widget    (const iWidget *, const char *id);
-const iPtrArray *findChildren_Widget  (const iWidget *, const char *id);
-iAny *  findParentClass_Widget(const iWidget *, const iAnyClass *class);
-iAny *  findFocusable_Widget(const iWidget *startFrom, enum iWidgetFocusDir focusDir);
-size_t  childCount_Widget   (const iWidget *);
-void    draw_Widget         (const iWidget *);
-void    drawBackground_Widget(const iWidget *);
-void    drawChildren_Widget (const iWidget *);
+const iString *id_Widget                (const iWidget *);
+int64_t flags_Widget                    (const iWidget *);
+iRect   bounds_Widget                   (const iWidget *); /* outer bounds */
+iRect   innerBounds_Widget              (const iWidget *);
+iInt2   localCoord_Widget               (const iWidget *, iInt2 coord);
+iBool   contains_Widget                 (const iWidget *, iInt2 coord);
+iBool   containsExpanded_Widget         (const iWidget *, iInt2 coord, int expand);
+iAny *  hitChild_Widget                 (const iWidget *, iInt2 coord);
+iAny *  findChild_Widget                (const iWidget *, const char *id);
+const iPtrArray *findChildren_Widget    (const iWidget *, const char *id);
+iAny *  findParentClass_Widget          (const iWidget *, const iAnyClass *class);
+iAny *  findFocusable_Widget            (const iWidget *startFrom, enum iWidgetFocusDir focusDir);
+size_t  childCount_Widget               (const iWidget *);
+void    draw_Widget                     (const iWidget *);
+void    drawBackground_Widget           (const iWidget *);
+void    drawChildren_Widget             (const iWidget *);
 
 iLocalDef int width_Widget(const iAnyObject *d) {
     if (d) {
diff --git a/src/ui/window.c b/src/ui/window.c
index 1c0c0394..e7945c62 100644
--- a/src/ui/window.c
+++ b/src/ui/window.c
@@ -1827,7 +1827,7 @@ void draw_Window(iWindow *d) {
         }
     }
 #endif
-    const int winFlags = SDL_GetWindowFlags(d->win);
+    const int   winFlags = SDL_GetWindowFlags(d->win);
     const iBool gotFocus = (winFlags & SDL_WINDOW_INPUT_FOCUS) != 0;
     /* Clear the window. The clear color is visible as a border around the window
        when the custom frame is being used. */ {