michael@0: /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: package org.mozilla.gecko.gfx;
michael@0: 
michael@0: import org.mozilla.gecko.mozglue.generatorannotations.WrapElementForJNI;
michael@0: import org.mozilla.gecko.util.FloatUtils;
michael@0: 
michael@0: import android.graphics.PointF;
michael@0: import android.graphics.RectF;
michael@0: import android.util.DisplayMetrics;
michael@0: 
michael@0: /**
michael@0:  * ImmutableViewportMetrics are used to store the viewport metrics
michael@0:  * in way that we can access a version of them from multiple threads
michael@0:  * without having to take a lock
michael@0:  */
michael@0: public class ImmutableViewportMetrics {
michael@0: 
michael@0:     // We need to flatten the RectF and FloatSize structures
michael@0:     // because Java doesn't have the concept of const classes
michael@0:     public final float pageRectLeft;
michael@0:     public final float pageRectTop;
michael@0:     public final float pageRectRight;
michael@0:     public final float pageRectBottom;
michael@0:     public final float cssPageRectLeft;
michael@0:     public final float cssPageRectTop;
michael@0:     public final float cssPageRectRight;
michael@0:     public final float cssPageRectBottom;
michael@0:     public final float viewportRectLeft;
michael@0:     public final float viewportRectTop;
michael@0:     public final float viewportRectRight;
michael@0:     public final float viewportRectBottom;
michael@0:     public final float marginLeft;
michael@0:     public final float marginTop;
michael@0:     public final float marginRight;
michael@0:     public final float marginBottom;
michael@0:     public final float zoomFactor;
michael@0:     public final boolean isRTL;
michael@0: 
michael@0:     public ImmutableViewportMetrics(DisplayMetrics metrics) {
michael@0:         viewportRectLeft   = pageRectLeft   = cssPageRectLeft   = 0;
michael@0:         viewportRectTop    = pageRectTop    = cssPageRectTop    = 0;
michael@0:         viewportRectRight  = pageRectRight  = cssPageRectRight  = metrics.widthPixels;
michael@0:         viewportRectBottom = pageRectBottom = cssPageRectBottom = metrics.heightPixels;
michael@0:         marginLeft = marginTop = marginRight = marginBottom = 0;
michael@0:         zoomFactor = 1.0f;
michael@0:         isRTL = false;
michael@0:     }
michael@0: 
michael@0:     /** This constructor is used by native code in AndroidJavaWrappers.cpp, be
michael@0:      * careful when modifying the signature.
michael@0:      */
michael@0:     @WrapElementForJNI(allowMultithread = true)
michael@0:     public ImmutableViewportMetrics(float aPageRectLeft, float aPageRectTop,
michael@0:         float aPageRectRight, float aPageRectBottom, float aCssPageRectLeft,
michael@0:         float aCssPageRectTop, float aCssPageRectRight, float aCssPageRectBottom,
michael@0:         float aViewportRectLeft, float aViewportRectTop, float aViewportRectRight,
michael@0:         float aViewportRectBottom, float aZoomFactor)
michael@0:     {
michael@0:         this(aPageRectLeft, aPageRectTop,
michael@0:              aPageRectRight, aPageRectBottom, aCssPageRectLeft,
michael@0:              aCssPageRectTop, aCssPageRectRight, aCssPageRectBottom,
michael@0:              aViewportRectLeft, aViewportRectTop, aViewportRectRight,
michael@0:              aViewportRectBottom, 0.0f, 0.0f, 0.0f, 0.0f, aZoomFactor, false);
michael@0:     }
michael@0: 
michael@0:     private ImmutableViewportMetrics(float aPageRectLeft, float aPageRectTop,
michael@0:         float aPageRectRight, float aPageRectBottom, float aCssPageRectLeft,
michael@0:         float aCssPageRectTop, float aCssPageRectRight, float aCssPageRectBottom,
michael@0:         float aViewportRectLeft, float aViewportRectTop, float aViewportRectRight,
michael@0:         float aViewportRectBottom, float aMarginLeft,
michael@0:         float aMarginTop, float aMarginRight,
michael@0:         float aMarginBottom, float aZoomFactor, boolean aIsRTL)
michael@0:     {
michael@0:         pageRectLeft = aPageRectLeft;
michael@0:         pageRectTop = aPageRectTop;
michael@0:         pageRectRight = aPageRectRight;
michael@0:         pageRectBottom = aPageRectBottom;
michael@0:         cssPageRectLeft = aCssPageRectLeft;
michael@0:         cssPageRectTop = aCssPageRectTop;
michael@0:         cssPageRectRight = aCssPageRectRight;
michael@0:         cssPageRectBottom = aCssPageRectBottom;
michael@0:         viewportRectLeft = aViewportRectLeft;
michael@0:         viewportRectTop = aViewportRectTop;
michael@0:         viewportRectRight = aViewportRectRight;
michael@0:         viewportRectBottom = aViewportRectBottom;
michael@0:         marginLeft = aMarginLeft;
michael@0:         marginTop = aMarginTop;
michael@0:         marginRight = aMarginRight;
michael@0:         marginBottom = aMarginBottom;
michael@0:         zoomFactor = aZoomFactor;
michael@0:         isRTL = aIsRTL;
michael@0:     }
michael@0: 
michael@0:     public float getWidth() {
michael@0:         return viewportRectRight - viewportRectLeft;
michael@0:     }
michael@0: 
michael@0:     public float getHeight() {
michael@0:         return viewportRectBottom - viewportRectTop;
michael@0:     }
michael@0: 
michael@0:     public float getWidthWithoutMargins() {
michael@0:         return viewportRectRight - viewportRectLeft - marginLeft - marginRight;
michael@0:     }
michael@0: 
michael@0:     public float getHeightWithoutMargins() {
michael@0:         return viewportRectBottom - viewportRectTop - marginTop - marginBottom;
michael@0:     }
michael@0: 
michael@0:     public PointF getOrigin() {
michael@0:         return new PointF(viewportRectLeft, viewportRectTop);
michael@0:     }
michael@0: 
michael@0:     public PointF getMarginOffset() {
michael@0:         if (isRTL) {
michael@0:             return new PointF(marginLeft - marginRight, marginTop);
michael@0:         }
michael@0:         return new PointF(marginLeft, marginTop);
michael@0:     }
michael@0: 
michael@0:     public FloatSize getSize() {
michael@0:         return new FloatSize(viewportRectRight - viewportRectLeft, viewportRectBottom - viewportRectTop);
michael@0:     }
michael@0: 
michael@0:     public RectF getViewport() {
michael@0:         return new RectF(viewportRectLeft,
michael@0:                          viewportRectTop,
michael@0:                          viewportRectRight,
michael@0:                          viewportRectBottom);
michael@0:     }
michael@0: 
michael@0:     public RectF getCssViewport() {
michael@0:         return RectUtils.scale(getViewport(), 1/zoomFactor);
michael@0:     }
michael@0: 
michael@0:     public RectF getPageRect() {
michael@0:         return new RectF(pageRectLeft, pageRectTop, pageRectRight, pageRectBottom);
michael@0:     }
michael@0: 
michael@0:     public float getPageWidth() {
michael@0:         return pageRectRight - pageRectLeft;
michael@0:     }
michael@0: 
michael@0:     public float getPageWidthWithMargins() {
michael@0:         return (pageRectRight - pageRectLeft) + marginLeft + marginRight;
michael@0:     }
michael@0: 
michael@0:     public float getPageHeight() {
michael@0:         return pageRectBottom - pageRectTop;
michael@0:     }
michael@0: 
michael@0:     public float getPageHeightWithMargins() {
michael@0:         return (pageRectBottom - pageRectTop) + marginTop + marginBottom;
michael@0:     }
michael@0: 
michael@0:     public RectF getCssPageRect() {
michael@0:         return new RectF(cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom);
michael@0:     }
michael@0: 
michael@0:     public RectF getOverscroll() {
michael@0:         return new RectF(Math.max(0, pageRectLeft - viewportRectLeft),
michael@0:                          Math.max(0, pageRectTop - viewportRectTop),
michael@0:                          Math.max(0, viewportRectRight - pageRectRight),
michael@0:                          Math.max(0, viewportRectBottom - pageRectBottom));
michael@0:     }
michael@0: 
michael@0:     /*
michael@0:      * Returns the viewport metrics that represent a linear transition between "this" and "to" at
michael@0:      * time "t", which is on the scale [0, 1). This function interpolates all values stored in
michael@0:      * the viewport metrics.
michael@0:      */
michael@0:     public ImmutableViewportMetrics interpolate(ImmutableViewportMetrics to, float t) {
michael@0:         return new ImmutableViewportMetrics(
michael@0:             FloatUtils.interpolate(pageRectLeft, to.pageRectLeft, t),
michael@0:             FloatUtils.interpolate(pageRectTop, to.pageRectTop, t),
michael@0:             FloatUtils.interpolate(pageRectRight, to.pageRectRight, t),
michael@0:             FloatUtils.interpolate(pageRectBottom, to.pageRectBottom, t),
michael@0:             FloatUtils.interpolate(cssPageRectLeft, to.cssPageRectLeft, t),
michael@0:             FloatUtils.interpolate(cssPageRectTop, to.cssPageRectTop, t),
michael@0:             FloatUtils.interpolate(cssPageRectRight, to.cssPageRectRight, t),
michael@0:             FloatUtils.interpolate(cssPageRectBottom, to.cssPageRectBottom, t),
michael@0:             FloatUtils.interpolate(viewportRectLeft, to.viewportRectLeft, t),
michael@0:             FloatUtils.interpolate(viewportRectTop, to.viewportRectTop, t),
michael@0:             FloatUtils.interpolate(viewportRectRight, to.viewportRectRight, t),
michael@0:             FloatUtils.interpolate(viewportRectBottom, to.viewportRectBottom, t),
michael@0:             FloatUtils.interpolate(marginLeft, to.marginLeft, t),
michael@0:             FloatUtils.interpolate(marginTop, to.marginTop, t),
michael@0:             FloatUtils.interpolate(marginRight, to.marginRight, t),
michael@0:             FloatUtils.interpolate(marginBottom, to.marginBottom, t),
michael@0:             FloatUtils.interpolate(zoomFactor, to.zoomFactor, t),
michael@0:             t >= 0.5 ? to.isRTL : isRTL);
michael@0:     }
michael@0: 
michael@0:     public ImmutableViewportMetrics setViewportSize(float width, float height) {
michael@0:         if (FloatUtils.fuzzyEquals(width, getWidth()) && FloatUtils.fuzzyEquals(height, getHeight())) {
michael@0:             return this;
michael@0:         }
michael@0: 
michael@0:         return new ImmutableViewportMetrics(
michael@0:             pageRectLeft, pageRectTop, pageRectRight, pageRectBottom,
michael@0:             cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom,
michael@0:             viewportRectLeft, viewportRectTop, viewportRectLeft + width, viewportRectTop + height,
michael@0:             marginLeft, marginTop, marginRight, marginBottom,
michael@0:             zoomFactor, isRTL);
michael@0:     }
michael@0: 
michael@0:     public ImmutableViewportMetrics setViewportOrigin(float newOriginX, float newOriginY) {
michael@0:         return new ImmutableViewportMetrics(
michael@0:             pageRectLeft, pageRectTop, pageRectRight, pageRectBottom,
michael@0:             cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom,
michael@0:             newOriginX, newOriginY, newOriginX + getWidth(), newOriginY + getHeight(),
michael@0:             marginLeft, marginTop, marginRight, marginBottom,
michael@0:             zoomFactor, isRTL);
michael@0:     }
michael@0: 
michael@0:     public ImmutableViewportMetrics setZoomFactor(float newZoomFactor) {
michael@0:         return new ImmutableViewportMetrics(
michael@0:             pageRectLeft, pageRectTop, pageRectRight, pageRectBottom,
michael@0:             cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom,
michael@0:             viewportRectLeft, viewportRectTop, viewportRectRight, viewportRectBottom,
michael@0:             marginLeft, marginTop, marginRight, marginBottom,
michael@0:             newZoomFactor, isRTL);
michael@0:     }
michael@0: 
michael@0:     public ImmutableViewportMetrics offsetViewportBy(float dx, float dy) {
michael@0:         return setViewportOrigin(viewportRectLeft + dx, viewportRectTop + dy);
michael@0:     }
michael@0: 
michael@0:     public ImmutableViewportMetrics offsetViewportByAndClamp(float dx, float dy) {
michael@0:         if (isRTL) {
michael@0:             return setViewportOrigin(
michael@0:                 Math.min(pageRectRight - getWidthWithoutMargins(), Math.max(viewportRectLeft + dx, pageRectLeft)),
michael@0:                 Math.max(pageRectTop, Math.min(viewportRectTop + dy, pageRectBottom - getHeightWithoutMargins())));
michael@0:         }
michael@0:         return setViewportOrigin(
michael@0:             Math.max(pageRectLeft, Math.min(viewportRectLeft + dx, pageRectRight - getWidthWithoutMargins())),
michael@0:             Math.max(pageRectTop, Math.min(viewportRectTop + dy, pageRectBottom - getHeightWithoutMargins())));
michael@0:     }
michael@0: 
michael@0:     public ImmutableViewportMetrics setPageRect(RectF pageRect, RectF cssPageRect) {
michael@0:         return new ImmutableViewportMetrics(
michael@0:             pageRect.left, pageRect.top, pageRect.right, pageRect.bottom,
michael@0:             cssPageRect.left, cssPageRect.top, cssPageRect.right, cssPageRect.bottom,
michael@0:             viewportRectLeft, viewportRectTop, viewportRectRight, viewportRectBottom,
michael@0:             marginLeft, marginTop, marginRight, marginBottom,
michael@0:             zoomFactor, isRTL);
michael@0:     }
michael@0: 
michael@0:     public ImmutableViewportMetrics setMargins(float left, float top, float right, float bottom) {
michael@0:         if (FloatUtils.fuzzyEquals(left, marginLeft)
michael@0:                 && FloatUtils.fuzzyEquals(top, marginTop)
michael@0:                 && FloatUtils.fuzzyEquals(right, marginRight)
michael@0:                 && FloatUtils.fuzzyEquals(bottom, marginBottom)) {
michael@0:             return this;
michael@0:         }
michael@0: 
michael@0:         return new ImmutableViewportMetrics(
michael@0:             pageRectLeft, pageRectTop, pageRectRight, pageRectBottom,
michael@0:             cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom,
michael@0:             viewportRectLeft, viewportRectTop, viewportRectRight, viewportRectBottom,
michael@0:             left, top, right, bottom, zoomFactor, isRTL);
michael@0:     }
michael@0: 
michael@0:     public ImmutableViewportMetrics setMarginsFrom(ImmutableViewportMetrics fromMetrics) {
michael@0:         return setMargins(fromMetrics.marginLeft,
michael@0:                           fromMetrics.marginTop,
michael@0:                           fromMetrics.marginRight,
michael@0:                           fromMetrics.marginBottom);
michael@0:     }
michael@0: 
michael@0:     public ImmutableViewportMetrics setIsRTL(boolean aIsRTL) {
michael@0:         if (isRTL == aIsRTL) {
michael@0:             return this;
michael@0:         }
michael@0: 
michael@0:         return new ImmutableViewportMetrics(
michael@0:             pageRectLeft, pageRectTop, pageRectRight, pageRectBottom,
michael@0:             cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom,
michael@0:             viewportRectLeft, viewportRectTop, viewportRectRight, viewportRectBottom,
michael@0:             marginLeft, marginTop, marginRight, marginBottom, zoomFactor, aIsRTL);
michael@0:     }
michael@0: 
michael@0:     /* This will set the zoom factor and re-scale page-size and viewport offset
michael@0:      * accordingly. The given focus will remain at the same point on the screen
michael@0:      * after scaling.
michael@0:      */
michael@0:     public ImmutableViewportMetrics scaleTo(float newZoomFactor, PointF focus) {
michael@0:         // cssPageRect* is invariant, since we're setting the scale factor
michael@0:         // here. The page rect is based on the CSS page rect.
michael@0:         float newPageRectLeft = cssPageRectLeft * newZoomFactor;
michael@0:         float newPageRectTop = cssPageRectTop * newZoomFactor;
michael@0:         float newPageRectRight = cssPageRectLeft + ((cssPageRectRight - cssPageRectLeft) * newZoomFactor);
michael@0:         float newPageRectBottom = cssPageRectTop + ((cssPageRectBottom - cssPageRectTop) * newZoomFactor);
michael@0: 
michael@0:         PointF origin = getOrigin();
michael@0:         origin.offset(focus.x, focus.y);
michael@0:         origin = PointUtils.scale(origin, newZoomFactor / zoomFactor);
michael@0:         origin.offset(-focus.x, -focus.y);
michael@0: 
michael@0:         return new ImmutableViewportMetrics(
michael@0:             newPageRectLeft, newPageRectTop, newPageRectRight, newPageRectBottom,
michael@0:             cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom,
michael@0:             origin.x, origin.y, origin.x + getWidth(), origin.y + getHeight(),
michael@0:             marginLeft, marginTop, marginRight, marginBottom,
michael@0:             newZoomFactor, isRTL);
michael@0:     }
michael@0: 
michael@0:     /** Clamps the viewport to remain within the page rect. */
michael@0:     private ImmutableViewportMetrics clamp(float marginLeft, float marginTop,
michael@0:                                            float marginRight, float marginBottom) {
michael@0:         RectF newViewport = getViewport();
michael@0:         PointF offset = getMarginOffset();
michael@0: 
michael@0:         // The viewport bounds ought to never exceed the page bounds.
michael@0:         if (newViewport.right > pageRectRight + marginLeft + marginRight)
michael@0:             newViewport.offset((pageRectRight + marginLeft + marginRight) - newViewport.right, 0);
michael@0:         if (newViewport.left < pageRectLeft)
michael@0:             newViewport.offset(pageRectLeft - newViewport.left, 0);
michael@0: 
michael@0:         if (newViewport.bottom > pageRectBottom + marginTop + marginBottom)
michael@0:             newViewport.offset(0, (pageRectBottom + marginTop + marginBottom) - newViewport.bottom);
michael@0:         if (newViewport.top < pageRectTop)
michael@0:             newViewport.offset(0, pageRectTop - newViewport.top);
michael@0: 
michael@0:         return new ImmutableViewportMetrics(
michael@0:             pageRectLeft, pageRectTop, pageRectRight, pageRectBottom,
michael@0:             cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom,
michael@0:             newViewport.left, newViewport.top, newViewport.right, newViewport.bottom,
michael@0:             marginLeft, marginTop, marginRight, marginBottom,
michael@0:             zoomFactor, isRTL);
michael@0:     }
michael@0: 
michael@0:     public ImmutableViewportMetrics clamp() {
michael@0:         return clamp(0, 0, 0, 0);
michael@0:     }
michael@0: 
michael@0:     public ImmutableViewportMetrics clampWithMargins() {
michael@0:         return clamp(marginLeft, marginTop,
michael@0:                      marginRight, marginBottom);
michael@0:     }
michael@0: 
michael@0:     public boolean fuzzyEquals(ImmutableViewportMetrics other) {
michael@0:         // Don't bother checking the pageRectXXX values because they are a product
michael@0:         // of the cssPageRectXXX values and the zoomFactor, except with more rounding
michael@0:         // error. Checking those is both inefficient and can lead to false negatives.
michael@0:         //
michael@0:         // This doesn't return false if the margins differ as none of the users
michael@0:         // of this function are interested in the margins in that way.
michael@0:         return FloatUtils.fuzzyEquals(cssPageRectLeft, other.cssPageRectLeft)
michael@0:             && FloatUtils.fuzzyEquals(cssPageRectTop, other.cssPageRectTop)
michael@0:             && FloatUtils.fuzzyEquals(cssPageRectRight, other.cssPageRectRight)
michael@0:             && FloatUtils.fuzzyEquals(cssPageRectBottom, other.cssPageRectBottom)
michael@0:             && FloatUtils.fuzzyEquals(viewportRectLeft, other.viewportRectLeft)
michael@0:             && FloatUtils.fuzzyEquals(viewportRectTop, other.viewportRectTop)
michael@0:             && FloatUtils.fuzzyEquals(viewportRectRight, other.viewportRectRight)
michael@0:             && FloatUtils.fuzzyEquals(viewportRectBottom, other.viewportRectBottom)
michael@0:             && FloatUtils.fuzzyEquals(zoomFactor, other.zoomFactor);
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public String toString() {
michael@0:         return "ImmutableViewportMetrics v=(" + viewportRectLeft + "," + viewportRectTop + ","
michael@0:                 + viewportRectRight + "," + viewportRectBottom + ") p=(" + pageRectLeft + ","
michael@0:                 + pageRectTop + "," + pageRectRight + "," + pageRectBottom + ") c=("
michael@0:                 + cssPageRectLeft + "," + cssPageRectTop + "," + cssPageRectRight + ","
michael@0:                 + cssPageRectBottom + ") m=(" + marginLeft + ","
michael@0:                 + marginTop + "," + marginRight + ","
michael@0:                 + marginBottom + ") z=" + zoomFactor + ", rtl=" + isRTL;
michael@0:     }
michael@0: }