Mobile: Dealing with keyboard height

The software keyboard obstructs part of the UI, so need to offset the view if the focused input widget would not be visible.

11 files changed, 160 insertions, 34 deletions

diff --git a/src/app.c b/src/app.c
index a7539203..ada142f0 100644
--- a/src/app.c
+++ b/src/app.c
@@ -820,6 +820,11 @@ iLocalDef iBool isWaitingAllowed_App_(iApp *d) {
         return iFalse;
     }
 #endif
+#if defined (iPlatformMobile)
+    if (!isFinished_Anim(&d->window->rootOffset)) {
+        return iFalse;
+    }
+#endif
     return !value_Atomic(&d->pendingRefresh) && isEmpty_SortedArray(&d->tickers);
 }
 
@@ -929,7 +934,7 @@ void processEvents_App(enum iAppEventMode eventMode) {
         }
     }
 #if defined (LAGRANGE_IDLE_SLEEP)
-    if (d->isIdling && !gotEvents) {
+    if (d->isIdling && !gotEvents && isFinished_Anim(&d->window->rootOffset)) {
         /* This is where we spend most of our time when idle. 60 Hz still quite a lot but we
            can't wait too long after the user tries to interact again with the app. In any
            case, on macOS SDL_WaitEvent() seems to use 10x more CPU time than sleeping. */
@@ -1135,8 +1140,7 @@ iMimeHooks *mimeHooks_App(void) {
 }
 
 iBool isLandscape_App(void) {
-    const iApp *d = &app_;
-    const iInt2 size = rootSize_Window(d->window);
+    const iInt2 size = rootSize_Window(get_Window());
     return size.x > size.y;
 }
 
@@ -1700,6 +1704,7 @@ iBool handleCommand_App(const char *cmd) {
 #if defined (iPlatformAppleMobile)
         /* Can't close the last on mobile. */
         if (tabCount_Widget(tabs) == 1) {
+            postCommand_App("navigate.home");
             return iTrue;
         }
 #endif
diff --git a/src/ios.m b/src/ios.m
index 5abf87df..4d1aac37 100644
--- a/src/ios.m
+++ b/src/ios.m
@@ -31,28 +31,63 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
 static iBool isSystemDarkMode_ = iFalse;
 static iBool isPhone_ = iFalse;
 
+static UIViewController *viewController_(iWindow *window) {
+    SDL_SysWMinfo wm;
+    SDL_VERSION(&wm.version);
+    if (SDL_GetWindowWMInfo(window->win, &wm)) {
+        return wm.info.uikit.window.rootViewController;
+    }
+    iAssert(false);
+    return NULL;
+}
+
+@interface KeyboardObserver : NSObject
+-(void)keyboardOnScreen:(NSNotification *)notification;
+@end
+
+@implementation KeyboardObserver
+-(void)keyboardOnScreen:(NSNotification *)notification {
+    NSDictionary *info   = notification.userInfo;
+    NSValue      *value  = info[UIKeyboardFrameEndUserInfoKey];
+    CGRect rawFrame      = [value CGRectValue];
+    UIView *view         = [viewController_(get_Window()) view];
+    CGRect keyboardFrame = [view convertRect:rawFrame fromView:nil];
+//    NSLog(@"keyboardFrame: %@", NSStringFromCGRect(keyboardFrame));
+    iWindow *window = get_Window();
+    const iInt2 rootSize = rootSize_Window(window);
+    const int keyTop = keyboardFrame.origin.y * window->pixelRatio;
+    setKeyboardHeight_Window(window, rootSize.y - keyTop);
+}
+
+-(void)keyboardOffScreen:(NSNotification *)notification {
+    setKeyboardHeight_Window(get_Window(), 0);
+}
+@end
+
 static void enableMouse_(iBool yes) {
     SDL_EventState(SDL_MOUSEBUTTONDOWN, yes);
     SDL_EventState(SDL_MOUSEMOTION, yes);
     SDL_EventState(SDL_MOUSEBUTTONUP, yes);
 }
 
+KeyboardObserver *keyObs_;
+
 void setupApplication_iOS(void) {
     enableMouse_(iFalse);
     NSString *deviceModel = [[UIDevice currentDevice] model];
     if ([deviceModel isEqualToString:@"iPhone"]) {
         isPhone_ = iTrue;
     }
-}
-
-static UIViewController *viewController_(iWindow *window) {
-    SDL_SysWMinfo wm;
-    SDL_VERSION(&wm.version);
-    if (SDL_GetWindowWMInfo(window->win, &wm)) {
-        return wm.info.uikit.window.rootViewController;
-    }
-    iAssert(false);
-    return NULL;
+    keyObs_ = [[KeyboardObserver alloc] init];
+    NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
+    [center addObserver:keyObs_
+               selector:@selector(keyboardOnScreen:)
+                   name:UIKeyboardWillShowNotification
+                 object:nil];
+    [center addObserver:keyObs_
+               selector:@selector(keyboardOffScreen:)
+                   name:UIKeyboardWillHideNotification
+                 object:nil];
 }
 
 static iBool isDarkMode_(iWindow *window) {
@@ -71,13 +106,15 @@ void safeAreaInsets_iOS(float *left, float *top, float *right, float *bottom) {
     UIViewController *ctl = viewController_(window);
     if (@available(iOS 11.0, *)) {
         const UIEdgeInsets safe = ctl.view.safeAreaInsets;
-        *left = safe.left * window->pixelRatio;
-        *top = safe.top * window->pixelRatio;
-        *right = safe.right * window->pixelRatio;
-        *bottom = safe.bottom * window->pixelRatio;
+        if (left) *left = safe.left * window->pixelRatio;
+        if (top) *top = safe.top * window->pixelRatio;
+        if (right) *right = safe.right * window->pixelRatio;
+        if (bottom) *bottom = safe.bottom * window->pixelRatio;
     } else {
-        // Fallback on earlier versions
-        *left = *top = *right = *bottom = 0.0f;
+        if (left) *left = 0.0f;
+        if (top) *top = 0.0f;
+        if (right) *right = 0.0f;
+        if (bottom) *bottom = 0.0f;
     }
 }
 
diff --git a/src/ui/inputwidget.c b/src/ui/inputwidget.c
index 3f178fc5..06bb9474 100644
--- a/src/ui/inputwidget.c
+++ b/src/ui/inputwidget.c
@@ -21,6 +21,7 @@ ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
 
 #include "inputwidget.h"
+#include "command.h"
 #include "paint.h"
 #include "util.h"
 #include "keys.h"
@@ -615,6 +616,17 @@ static iBool processEvent_InputWidget_(iInputWidget *d, const SDL_Event *ev) {
         }
         return iFalse;
     }
+    else if (isCommand_UserEvent(ev, "keyboard.changed")) {
+        if (isFocused_Widget(d) && arg_Command(command_UserEvent(ev))) {
+            iRect rect = bounds_Widget(w);
+            rect.pos.y -= value_Anim(&get_Window()->rootOffset);
+            const iInt2 visRoot = visibleRootSize_Window(get_Window());
+            if (bottom_Rect(rect) > visRoot.y) {
+                setValue_Anim(&get_Window()->rootOffset, -(bottom_Rect(rect) - visRoot.y), 250);
+            }
+        }
+        return iFalse;
+    }
     else if (isMetricsChange_UserEvent(ev)) {
         updateMetrics_InputWidget_(d);
     }
diff --git a/src/ui/lookupwidget.c b/src/ui/lookupwidget.c
index 10039e10..eabfc7d2 100644
--- a/src/ui/lookupwidget.c
+++ b/src/ui/lookupwidget.c
@@ -36,6 +36,10 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
 #include "util.h"
 #include "visited.h"
 
+#if defined (iPlatformAppleMobile)
+#   include "../ios.h"
+#endif
+
 #include <the_Foundation/mutex.h>
 #include <the_Foundation/thread.h>
 #include <the_Foundation/regexp.h>
@@ -641,8 +645,9 @@ static iBool processEvent_LookupWidget_(iLookupWidget *d, const SDL_Event *ev) {
     if (isMetricsChange_UserEvent(ev)) {
         updateMetrics_LookupWidget_(d);
     }
-    else if (isResize_UserEvent(ev) || (equal_Command(cmd, "layout.changed") &&
-                                        equal_Rangecc(range_Command(cmd, "id"), "navbar"))) {
+    else if (isResize_UserEvent(ev) || equal_Command(cmd, "keyboard.changed") ||
+             (equal_Command(cmd, "layout.changed") &&
+              equal_Rangecc(range_Command(cmd, "id"), "navbar"))) {
         /* Position the lookup popup under the URL bar. */ {
             const iWindow *window = get_Window();
             const iInt2 rootSize = rootSize_Window(window);
@@ -651,13 +656,13 @@ static iBool processEvent_LookupWidget_(iLookupWidget *d, const SDL_Event *ev) {
                                       (rootSize.y - bottom_Rect(navBarBounds)) / 2));
             setPos_Widget(w, bottomLeft_Rect(bounds_Widget(findWidget_App("url"))));
 #if defined (iPlatformAppleMobile)
-            /* TODO: Ask the system how tall the keyboard is. */ {
-                if (isLandscape_App()) {
-                    w->rect.size.y = rootSize.y * 4 / 10;
-                }
-                else if (deviceType_App() == phone_AppDeviceType) {
-                    w->rect.size.x = rootSize.x;
-                    w->rect.pos.x  = 0;
+            /* Adjust height based on keyboard size. */ {
+                w->rect.size.y = visibleRootSize_Window(window).y - top_Rect(bounds_Widget(w));
+                if (deviceType_App() == phone_AppDeviceType) {
+                    float l, r;
+                    safeAreaInsets_iOS(&l, NULL, &r, NULL);
+                    w->rect.size.x = rootSize.x - l - r;
+                    w->rect.pos.x  = l;
                 }
             }
 #endif
diff --git a/src/ui/text.c b/src/ui/text.c
index d3b8df37..b08bdc60 100644
--- a/src/ui/text.c
+++ b/src/ui/text.c
@@ -53,6 +53,7 @@ int enableHalfPixelGlyphs_Text = iTrue; /* debug setting */
 int enableKerning_Text         = iTrue; /* looking up kern pairs is slow */
 
 static iBool enableRaster_Text_ = iTrue;
+static int   numPendingRasterization_Text_ = 0;
 
 enum iGlyphFlag {
     rasterized0_GlyphFlag = iBit(1),    /* zero offset */
@@ -423,6 +424,7 @@ static void initCache_Text_(iText *d) {
                                  d->cacheSize.x,
                                  d->cacheSize.y);    
     SDL_SetTextureBlendMode(d->cache, SDL_BLENDMODE_BLEND);
+    numPendingRasterization_Text_ = 0;
 }
 
 static void deinitCache_Text_(iText *d) {
@@ -501,6 +503,10 @@ void resetFonts_Text(void) {
     initFonts_Text_(d);
 }
 
+int numPendingGlyphs_Text(void) {
+    return numPendingRasterization_Text_;
+}
+
 iLocalDef iFont *font_Text_(enum iFontId id) {
     return &text_.fonts[id & mask_FontId];
 }
@@ -569,7 +575,7 @@ static void allocate_Font_(iFont *d, iGlyph *glyph, int hoff) {
     }
 }
 
-static void cache_Font_(iFont *d, iGlyph *glyph, int hoff) {
+static iBool cache_Font_(iFont *d, iGlyph *glyph, int hoff) {
     iText *       txt     = &text_;
     SDL_Renderer *render  = txt->render;
     SDL_Texture * tex     = NULL;
@@ -590,6 +596,7 @@ static void cache_Font_(iFont *d, iGlyph *glyph, int hoff) {
     if (surface) {
         SDL_FreeSurface(surface);
     }
+    return isRasterized_Glyph_(glyph, hoff);
 }
 
 iLocalDef iFont *characterFont_Font_(iFont *d, iChar ch, uint32_t *glyphIndex) {
@@ -659,15 +666,22 @@ static const iGlyph *glyph_Font_(iFont *d, iChar ch) {
         allocate_Font_(font, glyph, 0);
         allocate_Font_(font, glyph, 1);
         insert_Hash(&font->glyphs, &glyph->node);
+        numPendingRasterization_Text_ += 2;
     }
     if (enableRaster_Text_ && !isFullyRasterized_Glyph_(glyph)) {
         SDL_Texture *oldTarget = SDL_GetRenderTarget(text_.render);
         SDL_SetRenderTarget(text_.render, text_.cache);
         if (!isRasterized_Glyph_(glyph, 0)) {
-            cache_Font_(font, glyph, 0);
+            if (cache_Font_(font, glyph, 0)) {
+                numPendingRasterization_Text_--;
+                iAssert(numPendingRasterization_Text_ >= 0);
+            }
         }
         if (!isRasterized_Glyph_(glyph, 1)) {
-            cache_Font_(font, glyph, 1); /* half-pixel offset */
+            if (cache_Font_(font, glyph, 1)) { /* half-pixel offset */
+                numPendingRasterization_Text_--;
+                iAssert(numPendingRasterization_Text_ >= 0);
+            }
         }
         SDL_SetRenderTarget(text_.render, oldTarget);
     }
diff --git a/src/ui/text.h b/src/ui/text.h
index f696b2e3..1118882d 100644
--- a/src/ui/text.h
+++ b/src/ui/text.h
@@ -161,6 +161,7 @@ void    setContentFont_Text     (enum iTextFont font);
 void    setHeadingFont_Text     (enum iTextFont font);
 void    setContentFontSize_Text (float fontSizeFactor); /* affects all except `default*` fonts */
 void    resetFonts_Text         (void);
+int     numPendingGlyphs_Text   (void);
 
 int     lineHeight_Text         (int fontId);
 iInt2   measure_Text            (int fontId, const char *text);
diff --git a/src/ui/touch.c b/src/ui/touch.c
index 27db0073..f15eda6f 100644
--- a/src/ui/touch.c
+++ b/src/ui/touch.c
@@ -190,6 +190,10 @@ static void update_TouchState_(void *ptr) {
         iForEach(Array, m, d->moms) {
             if (numSteps == 0) break;
             iMomentum *mom = m.value;
+            if (!mom->affinity) {
+                remove_ArrayIterator(&m);
+                continue;
+            }
             for (int step = 0; step < numSteps; step++) {
                 mulvf_F3(&mom->velocity, momFriction);
                 addv_F3(&mom->accum, mulf_F3(mom->velocity, stepDurationMs / 1000.0f));
@@ -248,8 +252,11 @@ static void dispatchButtonUp_Touch_(iFloat3 pos) {
 static iWidget *findOverflowScrollable_Widget_(iWidget *d) {
     const iInt2 rootSize = rootSize_Window(get_Window());
     for (iWidget *w = d; w; w = parent_Widget(w)) {
-        if (flags_Widget(w) & overflowScrollable_WidgetFlag && height_Widget(w) > rootSize.y) {
-            return w;
+        if (flags_Widget(w) & overflowScrollable_WidgetFlag) {
+            if (height_Widget(w) > rootSize.y && !hasVisibleChildOnTop_Widget(w)) {
+                return w;
+            }
+            return NULL;
         }
     }
     return NULL;
@@ -262,9 +269,13 @@ iBool processEvent_Touch(const SDL_Event *ev) {
     }
     iTouchState *d = touchState_();
     iWindow *window = get_Window();
+    if (!isFinished_Anim(&window->rootOffset)) {
+        return iFalse;
+    }
     const iInt2 rootSize = rootSize_Window(window);
     const SDL_TouchFingerEvent *fing = &ev->tfinger;
-    const iFloat3 pos = init_F3(fing->x * rootSize.x, fing->y * rootSize.y, 0); /* pixels */
+    const iFloat3 pos = add_F3(init_F3(fing->x * rootSize.x, fing->y * rootSize.y, 0), /* pixels */
+                               init_F3(0, -value_Anim(&window->rootOffset), 0));
     const uint32_t nowTime = SDL_GetTicks();
     if (ev->type == SDL_FINGERDOWN) {
         /* Register the new touch. */
diff --git a/src/ui/widget.c b/src/ui/widget.c
index c54ea444..2381548a 100644
--- a/src/ui/widget.c
+++ b/src/ui/widget.c
@@ -507,6 +507,9 @@ iRect bounds_Widget(const iWidget *d) {
         }
         addv_I2(&bounds.pos, pos);
     }
+#if defined (iPlatformMobile)
+    bounds.pos.y += value_Anim(&get_Window()->rootOffset);
+#endif
     return bounds;
 }
 
@@ -1131,6 +1134,19 @@ static void printTree_Widget_(const iWidget *d, int indent) {
     }
 }
 
+iBool hasVisibleChildOnTop_Widget(const iWidget *parent) {
+    iConstForEach(ObjectList, i, parent->children) {
+        const iWidget *child = i.object;
+        if (~child->flags & hidden_WidgetFlag && child->flags & keepOnTop_WidgetFlag) {
+            return iTrue;
+        }
+        if (hasVisibleChildOnTop_Widget(child)) {
+            return iTrue;
+        }
+    }
+    return iFalse;
+}
+
 void printTree_Widget(const iWidget *d) {
     printTree_Widget_(d, 0);
 }
diff --git a/src/ui/widget.h b/src/ui/widget.h
index b1ee8c73..602e86cb 100644
--- a/src/ui/widget.h
+++ b/src/ui/widget.h
@@ -232,6 +232,7 @@ iWidget *hover_Widget       (void);
 void    unhover_Widget      (void);
 void    setMouseGrab_Widget (iWidget *);
 iWidget *mouseGrab_Widget   (void);
+iBool   hasVisibleChildOnTop_Widget(const iWidget *parent);
 void    printTree_Widget    (const iWidget *);
 
 iBool   equalWidget_Command (const char *cmd, const iWidget *widget, const char *checkCommand);
diff --git a/src/ui/window.c b/src/ui/window.c
index bf7214f4..9ff22d35 100644
--- a/src/ui/window.c
+++ b/src/ui/window.c
@@ -1136,6 +1136,7 @@ static void updateRootSize_Window_(iWindow *d, iBool notifyAlways) {
     iInt2 *size = &d->root->rect.size;
     const iInt2 oldSize = *size;
     SDL_GetRendererOutputSize(d->render, &size->x, &size->y);
+    size->y -= d->keyboardHeight;
     if (notifyAlways || !isEqual_I2(oldSize, *size)) {
         const iBool isHoriz = (d->place.lastNotifiedSize.x != size->x);
         const iBool isVert  = (d->place.lastNotifiedSize.y != size->y);
@@ -1287,6 +1288,8 @@ void init_Window(iWindow *d, iRect rect) {
     d->isMouseInside = iTrue;
     d->ignoreClick = iFalse;
     d->focusGainedAt = 0;
+    d->keyboardHeight = 0;
+    init_Anim(&d->rootOffset, 0.0f);
     uint32_t flags = 0;
 #if defined (iPlatformAppleDesktop)
     SDL_SetHint(SDL_HINT_RENDER_DRIVER, shouldDefaultToMetalRenderer_MacOS() ? "metal" : "opengl");
@@ -1704,6 +1707,7 @@ void draw_Window(iWindow *d) {
     if (d->isDrawFrozen) {
         return;
     }
+//    printf("num pending: %d\n", numPendingGlyphs_Text());
     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
@@ -1797,6 +1801,10 @@ iInt2 rootSize_Window(const iWindow *d) {
     return d ? d->root->rect.size : zero_I2();
 }
 
+iInt2 visibleRootSize_Window(const iWindow *d) {
+    return addY_I2(rootSize_Window(d), -d->keyboardHeight);
+}
+
 iInt2 coord_Window(const iWindow *d, int x, int y) {
 #if defined (iPlatformMsys) || defined (iPlatformLinux)
     /* On Windows, surface coordinates are in pixels. */
@@ -1828,6 +1836,18 @@ iWindow *get_Window(void) {
     return theWindow_;
 }
 
+void setKeyboardHeight_Window(iWindow *d, int height) {
+    if (d->keyboardHeight != height) {
+        d->keyboardHeight = height;
+        if (height == 0) {
+            setFlags_Anim(&d->rootOffset, easeBoth_AnimFlag, iTrue);
+            setValue_Anim(&d->rootOffset, 0, 250);
+        }
+        postCommandf_App("keyboard.changed arg:%d", height);
+        postRefresh_App();
+    }
+}
+
 void setSnap_Window(iWindow *d, int snapMode) {
     if (!prefs_App()->customFrame) {
         if (snapMode == maximized_WindowSnap) {
diff --git a/src/ui/window.h b/src/ui/window.h
index 7cd29d4b..8bc9911c 100644
--- a/src/ui/window.h
+++ b/src/ui/window.h
@@ -75,6 +75,8 @@ struct Impl_Window {
     SDL_Cursor *  cursors[SDL_NUM_SYSTEM_CURSORS];
     SDL_Cursor *  pendingCursor;
     int           loadAnimTimer;
+    iAnim         rootOffset;
+    int           keyboardHeight; /* mobile software keyboards */
 };
 
 iBool       processEvent_Window     (iWindow *, const SDL_Event *);
@@ -86,9 +88,11 @@ void        setUiScale_Window       (iWindow *, float uiScale);
 void        setFreezeDraw_Window    (iWindow *, iBool freezeDraw);
 void        setCursor_Window        (iWindow *, int cursor);
 void        setSnap_Window          (iWindow *, int snapMode);
+void        setKeyboardHeight_Window(iWindow *, int height);
 
 uint32_t    id_Window               (const iWindow *);
 iInt2       rootSize_Window         (const iWindow *);
+iInt2       visibleRootSize_Window  (const iWindow *); /* may be obstructed by software keyboard */
 float       uiScale_Window          (const iWindow *);
 iInt2       coord_Window            (const iWindow *, int x, int y);
 iInt2       mouseCoord_Window       (const iWindow *);