/* Communication module for Android terminals. -*- c-file-style: "GNU" -*- Copyright (C) 2023-2024 Free Software Foundation, Inc. This file is part of GNU Emacs. GNU Emacs is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. GNU Emacs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Emacs. If not, see . */ package org.gnu.emacs; import android.content.Context; import android.text.InputType; import android.view.ContextMenu; import android.view.DragEvent; import android.view.View; import android.view.KeyEvent; import android.view.MotionEvent; import android.view.ViewGroup; import android.view.ViewTreeObserver; import android.view.WindowInsets; import android.view.inputmethod.EditorInfo; import android.view.inputmethod.InputConnection; import android.view.inputmethod.InputMethodManager; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Rect; import android.graphics.Region; import android.graphics.Paint; import android.os.Build; import android.util.Log; /* This is an Android view which has a back and front buffer. When swapBuffers is called, the back buffer is swapped to the front buffer, and any damage is invalidated. frontBitmap and backBitmap are modified and used both from the UI and the Emacs thread. As a result, there is a lock held during all drawing operations. It is also a ViewGroup, as it also lays out children. */ public final class EmacsView extends ViewGroup implements ViewTreeObserver.OnGlobalLayoutListener { public static final String TAG = "EmacsView"; /* The associated EmacsWindow. */ public EmacsWindow window; /* The buffer bitmap. */ public Bitmap bitmap; /* The associated canvases. */ public Canvas canvas; /* The damage region. */ public Region damageRegion; /* The associated surface view. */ private EmacsSurfaceView surfaceView; /* Whether or not a configure event must be sent for the next layout event regardless of what changed. */ public boolean mustReportLayout; /* Whether or not bitmaps must be recreated upon the next call to getBitmap. */ private boolean bitmapDirty; /* Whether or not a popup is active. */ private boolean popupActive; /* The current context menu. */ private EmacsContextMenu contextMenu; /* The last measured width and height. */ private int measuredWidth, measuredHeight; /* Object acting as a lock for those values. */ private Object dimensionsLock; /* The serial of the last clip rectangle change. */ private long lastClipSerial; /* The InputMethodManager for this view's context. */ public InputMethodManager imManager; /* Whether or not this view is attached to a window. */ public boolean isAttachedToWindow; /* Whether or not this view should have the on screen keyboard displayed whenever possible. */ public boolean isCurrentlyTextEditor; /* The associated input connection. */ private EmacsInputConnection inputConnection; /* The current IC mode. See `android_reset_ic' for more details. */ private int icMode; /* The number of calls to `resetIC' to have taken place the last time an InputConnection was created. */ public long icSerial; /* The number of calls to `recetIC' that have taken place. */ public volatile long icGeneration; public EmacsView (EmacsWindow window) { super (EmacsService.SERVICE); Object tem; Context context; this.window = window; this.damageRegion = new Region (); setFocusable (true); setFocusableInTouchMode (true); /* Create the surface view. */ this.surfaceView = new EmacsSurfaceView (this); addView (this.surfaceView); /* Get rid of the default focus highlight. */ if (Build.VERSION.SDK_INT > Build.VERSION_CODES.O) setDefaultFocusHighlightEnabled (false); /* Obtain the input method manager. */ context = getContext (); tem = context.getSystemService (Context.INPUT_METHOD_SERVICE); imManager = (InputMethodManager) tem; /* Add this view as its own global layout listener. */ getViewTreeObserver ().addOnGlobalLayoutListener (this); /* Create an object used as a lock. */ this.dimensionsLock = new Object (); } private void handleDirtyBitmap () { Bitmap oldBitmap; int measuredWidth, measuredHeight; synchronized (dimensionsLock) { /* Load measuredWidth and measuredHeight. */ measuredWidth = this.measuredWidth; measuredHeight = this.measuredHeight; } if (measuredWidth == 0 || measuredHeight == 0) return; if (!isAttachedToWindow) return; /* If bitmap is the same width and height as the measured width and height, there is no need to do anything. Avoid allocating the extra bitmap. */ if (bitmap != null && (bitmap.getWidth () == measuredWidth && bitmap.getHeight () == measuredHeight)) { bitmapDirty = false; return; } /* Save the old bitmap. */ oldBitmap = bitmap; /* Recreate the back buffer bitmap. */ bitmap = Bitmap.createBitmap (measuredWidth, measuredHeight, Bitmap.Config.ARGB_8888); bitmap.eraseColor (window.background | 0xff000000); /* And canvases. */ canvas = new Canvas (bitmap); canvas.save (); /* Since the clip rectangles have been cleared, clear the clip rectangle ID. */ lastClipSerial = 0; /* Copy over the contents of the old bitmap. */ if (oldBitmap != null) canvas.drawBitmap (oldBitmap, 0f, 0f, new Paint ()); bitmapDirty = false; /* Explicitly free the old bitmap's memory. */ if (oldBitmap != null) oldBitmap.recycle (); /* Some Android versions still don't free the bitmap until the next GC. */ Runtime.getRuntime ().gc (); } public synchronized void explicitlyDirtyBitmap () { bitmapDirty = true; } public synchronized Bitmap getBitmap () { if (bitmapDirty || bitmap == null) handleDirtyBitmap (); return bitmap; } public synchronized Canvas getCanvas (EmacsGC gc) { int i; if (bitmapDirty || bitmap == null) handleDirtyBitmap (); if (canvas == null) return null; /* Update clip rectangles if necessary. */ if (gc.clipRectID != lastClipSerial) { canvas.restore (); canvas.save (); if (gc.real_clip_rects != null) { for (i = 0; i < gc.real_clip_rects.length; ++i) canvas.clipRect (gc.real_clip_rects[i]); } lastClipSerial = gc.clipRectID; } return canvas; } public void prepareForLayout (int wantedWidth, int wantedHeight) { synchronized (dimensionsLock) { measuredWidth = wantedWidth; measuredHeight = wantedWidth; } } @Override protected void onMeasure (int widthMeasureSpec, int heightMeasureSpec) { Rect measurements; int width, height; /* Return the width and height of the window regardless of what the parent says. */ measurements = window.getGeometry (); width = measurements.width (); height = measurements.height (); /* Now apply any extra requirements in widthMeasureSpec and heightMeasureSpec. */ if (MeasureSpec.getMode (widthMeasureSpec) == MeasureSpec.EXACTLY) width = MeasureSpec.getSize (widthMeasureSpec); else if (MeasureSpec.getMode (widthMeasureSpec) == MeasureSpec.AT_MOST && width > MeasureSpec.getSize (widthMeasureSpec)) width = MeasureSpec.getSize (widthMeasureSpec); if (MeasureSpec.getMode (heightMeasureSpec) == MeasureSpec.EXACTLY) height = MeasureSpec.getSize (heightMeasureSpec); else if (MeasureSpec.getMode (heightMeasureSpec) == MeasureSpec.AT_MOST && height > MeasureSpec.getSize (heightMeasureSpec)) height = MeasureSpec.getSize (heightMeasureSpec); super.setMeasuredDimension (width, height); } /* Return whether this view's window is focused. This is made necessary by Android 11's unreliable dispatch of onWindowFocusChanged prior to gesture navigation away from a frame. */ public boolean checkWindowFocus () { EmacsActivity activity; Object consumer; consumer = window.getAttachedConsumer (); if (!(consumer instanceof EmacsActivity)) return false; activity = (EmacsActivity) consumer; return activity.hasWindowFocus (); } /* Note that the monitor lock for the window must never be held from within the lock for the view, because the window also locks the other way around. */ @Override protected void onLayout (boolean changed, int left, int top, int right, int bottom) { int count, i, oldMeasuredWidth, oldMeasuredHeight; View child; Rect windowRect; boolean needExpose; WindowInsets rootWindowInsets; count = getChildCount (); needExpose = false; synchronized (dimensionsLock) { /* Load measuredWidth and measuredHeight. */ oldMeasuredWidth = measuredWidth; oldMeasuredHeight = measuredHeight; /* Set measuredWidth and measuredHeight. */ measuredWidth = right - left; measuredHeight = bottom - top; } /* If oldMeasuredHeight or oldMeasuredWidth are wrong, set changed to true as well. */ if (right - left != oldMeasuredWidth || bottom - top != oldMeasuredHeight) changed = true; /* Dirty the back buffer if the layout change resulted in the view being resized. */ if (changed) { explicitlyDirtyBitmap (); /* Expose the window upon a change in the view's size. */ if (right - left > oldMeasuredWidth || bottom - top > oldMeasuredHeight) needExpose = true; /* This might return NULL if this view is not attached. */ if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) { /* If a toplevel view is focused and isCurrentlyTextEditor is enabled when the IME is hidden, clear isCurrentlyTextEditor so it isn't shown again if the user dismisses Emacs before returning. */ rootWindowInsets = getRootWindowInsets (); if (isCurrentlyTextEditor && rootWindowInsets != null && isAttachedToWindow && !rootWindowInsets.isVisible (WindowInsets.Type.ime ()) /* N.B. that the keyboard is dismissed during gesture navigation under Android 30, but the system is quite temperamental regarding whether the window is focused at that point. Ideally isCurrentlyTextEditor shouldn't be reset in that case, but detecting that situation appears to be impossible. Sigh. */ && (window == EmacsActivity.focusedWindow && hasWindowFocus ())) isCurrentlyTextEditor = false; } } for (i = 0; i < count; ++i) { child = getChildAt (i); if (child == surfaceView) child.layout (0, 0, right - left, bottom - top); else if (child.getVisibility () != GONE) { if (!(child instanceof EmacsView)) continue; /* What to do: lay out the view precisely according to its window rect. */ windowRect = ((EmacsView) child).window.getGeometry (); child.layout (windowRect.left, windowRect.top, windowRect.right, windowRect.bottom); } } /* Now report the layout change to the window. */ if (changed || mustReportLayout) { mustReportLayout = false; window.viewLayout (left, top, right, bottom); } if (needExpose) EmacsNative.sendExpose (this.window.handle, 0, 0, right - left, bottom - top); } public void damageRect (Rect damageRect) { EmacsService.checkEmacsThread (); damageRegion.union (damageRect); } /* This function enables damage to be recorded without consing a new Rect object. */ public void damageRect (int left, int top, int right, int bottom) { EmacsService.checkEmacsThread (); damageRegion.op (left, top, right, bottom, Region.Op.UNION); } /* This method is called from both the UI thread and the Emacs thread. */ public void swapBuffers () { Canvas canvas; Rect damageRect; Bitmap bitmap; /* Make sure this function is called only from the Emacs thread. */ EmacsService.checkEmacsThread (); damageRect = null; /* Now see if there is a damage region. */ if (damageRegion.isEmpty ()) return; /* And extract and clear the damage region. */ damageRect = damageRegion.getBounds (); damageRegion.setEmpty (); bitmap = getBitmap (); /* Transfer the bitmap to the surface view, then invalidate it. */ surfaceView.setBitmap (bitmap, damageRect); } @Override public boolean onKeyPreIme (int keyCode, KeyEvent event) { /* Several Android systems intercept key events representing C-SPC. Avert this by detecting C-SPC events here and relaying them directly to onKeyDown. Make this optional though, since some input methods also leverage C-SPC as a shortcut for switching languages. */ if ((keyCode == KeyEvent.KEYCODE_SPACE && (window.eventModifiers (event) & KeyEvent.META_CTRL_MASK) != 0) && !EmacsNative.shouldForwardCtrlSpace ()) return onKeyDown (keyCode, event); return super.onKeyPreIme (keyCode, event); } @Override public boolean onKeyDown (int keyCode, KeyEvent event) { if ((keyCode == KeyEvent.KEYCODE_VOLUME_UP || keyCode == KeyEvent.KEYCODE_VOLUME_DOWN || keyCode == KeyEvent.KEYCODE_VOLUME_MUTE) && !EmacsNative.shouldForwardMultimediaButtons ()) return false; window.onKeyDown (keyCode, event); return true; } @Override public boolean onKeyMultiple (int keyCode, int repeatCount, KeyEvent event) { if ((keyCode == KeyEvent.KEYCODE_VOLUME_UP || keyCode == KeyEvent.KEYCODE_VOLUME_DOWN || keyCode == KeyEvent.KEYCODE_VOLUME_MUTE) && !EmacsNative.shouldForwardMultimediaButtons ()) return false; window.onKeyDown (keyCode, event); return true; } @Override public boolean onKeyUp (int keyCode, KeyEvent event) { if ((keyCode == KeyEvent.KEYCODE_VOLUME_UP || keyCode == KeyEvent.KEYCODE_VOLUME_DOWN || keyCode == KeyEvent.KEYCODE_VOLUME_MUTE) && !EmacsNative.shouldForwardMultimediaButtons ()) return false; window.onKeyUp (keyCode, event); return true; } @Override public void onFocusChanged (boolean gainFocus, int direction, Rect previouslyFocusedRect) { window.onFocusChanged (gainFocus); super.onFocusChanged (gainFocus, direction, previouslyFocusedRect); } @Override public boolean onGenericMotionEvent (MotionEvent motion) { return window.onGenericMotionEvent (motion); } @Override public boolean onTouchEvent (MotionEvent motion) { return window.onTouchEvent (motion); } @Override public boolean onDragEvent (DragEvent drag) { /* Inter-program drag and drop isn't supported under Android 23 and earlier. */ if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) return false; return window.onDragEvent (drag); } private void moveChildToBack (View child) { int index; index = indexOfChild (child); if (index > 0) { detachViewFromParent (index); /* The view at 0 is the surface view. */ attachViewToParent (child, 1, child.getLayoutParams ()); } } /* The following four functions must not be called if the view has no parent, or is parented to an activity. */ public void raise () { EmacsView parent; parent = (EmacsView) getParent (); if (parent.indexOfChild (this) == parent.getChildCount () - 1) return; parent.bringChildToFront (this); } public void lower () { EmacsView parent; parent = (EmacsView) getParent (); if (parent.indexOfChild (this) == 1) return; parent.moveChildToBack (this); } public void moveAbove (EmacsView view) { EmacsView parent; int index; parent = (EmacsView) getParent (); if (parent != view.getParent ()) throw new IllegalStateException ("Moving view above non-sibling"); index = parent.indexOfChild (this); parent.detachViewFromParent (index); index = parent.indexOfChild (view); parent.attachViewToParent (this, index + 1, getLayoutParams ()); } public void moveBelow (EmacsView view) { EmacsView parent; int index; parent = (EmacsView) getParent (); if (parent != view.getParent ()) throw new IllegalStateException ("Moving view above non-sibling"); index = parent.indexOfChild (this); parent.detachViewFromParent (index); index = parent.indexOfChild (view); parent.attachViewToParent (this, index, getLayoutParams ()); } @Override protected void onCreateContextMenu (ContextMenu menu) { if (contextMenu == null) return; contextMenu.expandTo (menu, this); } public boolean popupMenu (EmacsContextMenu menu, int xPosition, int yPosition, boolean force) { if (popupActive && !force) return false; /* Android will permanently cease to display any popup menus at all if the list of menu items is empty. Prevent this by promptly returning if there are no menu items. */ if (menu.menuItems.isEmpty ()) return false; contextMenu = menu; popupActive = true; /* Use showContextMenu (float, float) on N to get actual popup behavior. */ if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) return showContextMenu ((float) xPosition, (float) yPosition); else return showContextMenu (); } public void cancelPopupMenu () { if (!popupActive) throw new IllegalStateException ("cancelPopupMenu called without" + " popupActive set"); contextMenu = null; popupActive = false; /* It is not possible to know with 100% certainty which activity is currently displaying the context menu. Loop through each activity and call `closeContextMenu' instead. */ for (EmacsWindowAttachmentManager.WindowConsumer consumer : EmacsWindowAttachmentManager.MANAGER.consumers) { if (consumer instanceof EmacsActivity) ((EmacsActivity) consumer).closeContextMenu (); } } @Override public synchronized void onDetachedFromWindow () { isAttachedToWindow = false; /* Recycle the bitmap and call GC. */ if (bitmap != null) bitmap.recycle (); bitmap = null; canvas = null; surfaceView.setBitmap (null, null); /* Collect the bitmap storage; it could be large. */ Runtime.getRuntime ().gc (); super.onDetachedFromWindow (); } @Override public synchronized void onAttachedToWindow () { isAttachedToWindow = true; /* Dirty the bitmap, as it was destroyed when onDetachedFromWindow was called. */ bitmapDirty = true; synchronized (dimensionsLock) { /* Now expose the view contents again. */ EmacsNative.sendExpose (this.window.handle, 0, 0, measuredWidth, measuredHeight); } super.onAttachedToWindow (); } public void showOnScreenKeyboard () { /* Specifying no flags at all tells the system the user asked for the input method to be displayed. */ imManager.showSoftInput (this, 0); isCurrentlyTextEditor = true; } public void hideOnScreenKeyboard () { imManager.hideSoftInputFromWindow (this.getWindowToken (), 0); isCurrentlyTextEditor = false; } @Override public InputConnection onCreateInputConnection (EditorInfo info) { int mode; int[] selection; /* Figure out what kind of IME behavior Emacs wants. */ mode = getICMode (); /* Make sure the input method never displays a full screen input box that obscures Emacs. */ info.imeOptions = EditorInfo.IME_FLAG_NO_FULLSCREEN; info.imeOptions |= EditorInfo.IME_FLAG_NO_EXTRACT_UI; /* Set a reasonable inputType. */ info.inputType = InputType.TYPE_CLASS_TEXT; /* If this fails or ANDROID_IC_MODE_NULL was requested, then don't initialize the input connection. */ if (mode == EmacsService.IC_MODE_NULL) { info.inputType = InputType.TYPE_NULL; return null; } /* Set icSerial. If icSerial < icGeneration, the input connection has been reset, and future input should be ignored until a new connection is created. */ icSerial = icGeneration; /* Reset flags set by the previous input method. */ EmacsNative.clearInputFlags (window.handle); /* Obtain the current position of point and set it as the selection. Don't do this under one specific situation: if `android_update_ic' is being called in the main thread, trying to synchronize with it can cause a dead lock in the IM manager. See icBeginSynchronous in EmacsService.java for more details. */ selection = EmacsService.viewGetSelection (window.handle); if (selection == null) { /* If the selection could not be obtained, return 0 by 0. However, ask for the selection position to be updated as soon as possible. */ selection = new int[] { 0, 0, }; EmacsNative.requestSelectionUpdate (window.handle); } if (mode == EmacsService.IC_MODE_ACTION) info.imeOptions |= EditorInfo.IME_ACTION_DONE; /* Set the initial selection fields. */ info.initialSelStart = selection[0]; info.initialSelEnd = selection[1]; /* Create the input connection if necessary. */ if (inputConnection == null) inputConnection = new EmacsInputConnection (this); else /* Clear several pieces of state in the input connection. */ inputConnection.reset (); /* Return the input connection. */ return inputConnection; } @Override public synchronized boolean onCheckIsTextEditor () { /* If value is true, then the system will display the on screen keyboard. */ return isCurrentlyTextEditor; } @Override public boolean isOpaque () { /* Returning true here allows the system to not draw the contents of windows underneath this view, thereby improving performance. */ return true; } public synchronized void setICMode (int icMode) { this.icMode = icMode; } public synchronized int getICMode () { return icMode; } @Override public void onGlobalLayout () { int[] locations; /* Get the absolute offset of this view and specify its left and top position in subsequent ConfigureNotify events. */ locations = new int[2]; getLocationInWindow (locations); window.notifyContentRectPosition (locations[0], locations[1]); } @Override public WindowInsets onApplyWindowInsets (WindowInsets insets) { WindowInsets rootWindowInsets; /* This function is called when window insets change, which encompasses input method visibility changes under Android 30 and later. If a toplevel view is focused and isCurrentlyTextEditor is enabled when the IME is hidden, clear isCurrentlyTextEditor so it isn't shown again if the user dismisses Emacs before returning. */ if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) return super.onApplyWindowInsets (insets); /* This might return NULL if this view is not attached. */ rootWindowInsets = getRootWindowInsets (); if (isCurrentlyTextEditor && rootWindowInsets != null && isAttachedToWindow && !rootWindowInsets.isVisible (WindowInsets.Type.ime ()) && window == EmacsActivity.focusedWindow) isCurrentlyTextEditor = false; return super.onApplyWindowInsets (insets); } };